thromboxane-b2 and Diabetic-Nephropathies

Topics: Animals; Anthraquinones; Cytokines; Diabetic Nephropathies; Drugs, Chinese Herbal; Emodin; Humans; Interleukin-6; Plants, Medicinal; Rheum; Superoxide Dismutase; Thromboxane B2; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Serum creatinine, immunoreactive serum and urine beta-2-microglobulin, plasma and urine thromboglobulin, plasma thromboxane-B2 levels and daily protein excretion were determinated in 61 insulin treated diabetic patients, comparing the different patient groups (complication free, nephropathy without azotaemia and nephropathy with azotaemia) with the control subjects. In the groups of all diabetic patients plasma and urine beta-thromboglobulin and plasma thromboxane-B2 levels were higher that in the controls. There was a positive significant correlation between urine beta-thromboglobulin and beta-2-microglobulin in the group without complication, and between the plasma beta thromboglobulin and beta-2-microglobulin, and plasma beta thromboglobulin and thromboxane levels in the diabetic group with azotaemia. In contradiction to some previous assumptions, the increased level of plasma beta-thromboglobulin reflects a real platelet hyperactivation also in patients with diabetic nephropathy. At the same time urine beta-thromboglobulin also increases. Determination of urine beta-thromboglobulin is more simple with less possibility of methodological error.

Topics: beta 2-Microglobulin; beta-Thromboglobulin; Blood Platelets; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Humans; Proteinuria; Thromboxane B2

To study the therapeutic effect of Astragalus injection (AI) in treating early stage diabetic nephropathy (DN) patients.. The total of 136 early diabetic nephropathy patients were randomly divided into two groups, 50 cases in the conventional treated group and 86 in the AI treated group, the therapeutic course being 3 weeks. Levels of plasma endothelin-1 (ET-1), 24 hrs urinary albumin excretion rate (uAER), and platelet granule membrane protein (GMP-140), 6-keto-prostaglandin F1 alpha(6-keto-PGF1 alpha), and thromboxane B2(TXB2) before and after treatment were determined by radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) respectively. Moreover, the above-mentioned criteria in 26 healthy subjects were also measured for control.. The plasma ET-1, GMP-140, TXB2 and uAER levels in DN patients were higher, but 6-keto-PGF1 alpha level was lower than those in healthy subjects. The above elevated criteria in DN patients could be lowered by AI treatment.. The pathogenesis and development of DN might be closely associated with the changes of plasma ET-1 level and platelet function. Astragalus could improve the above-mentioned changes in patients of early stage DN.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Astragalus propinquus; Diabetic Nephropathies; Drugs, Chinese Herbal; Endothelin-1; Female; Humans; Infusions, Intravenous; Male; Middle Aged; P-Selectin; Phytotherapy; Platelet Activation; Thromboxane B2

Picotamide both inhibits thromboxane synthetase and acts as a thromboxane antagonist at the receptor level. We investigated the long-term effect of picotamide on urinary albumin excretion (UAE) at rest and induced by exercise in 30 type 2 diabetic patients who were normotensive and had microalbuminuria while at rest. The subjects of our study had a mean age of 52.5 +/- 1.6 years, BMI of 28.5 +/- 0.7 kg/m2, diabetes duration of 9.1 +/- 1.8 years, and HbA1c of 7.0 +/- 0.8%. The study was a randomized double-blind placebo-controlled trial. The patients were randomly allocated to receive for 1 year either picotamide, 300 mg, 3 tablets/day, or placebo, 3 tablets/day. The patients were asked to visit our outpatient clinic after 1, 3, 6, 9, and 12 months of treatment. At all times, blood pressure, microalbuminuria at rest, blood glucose, serum creatinine, serum picotamide, and creatinine clearance were measured; at baseline and after 6 and 12 months, all patients underwent submaximal physical exercise. After 6 months of picotamide, baseline and exercise-induced microalbuminuria were significantly decreased (up to one-third) as compared with the baseline and placebo level, with no further drops at month 12 of picotamide treatment. On placebo treatment, UAE at rest and after exercise was slightly increased compared with baseline values. The effects of picotamide occurred without significant side effects or changes in either blood pressure levels or glycometabolic control. Our study is the first long-term intervention trial in type 2 diabetes showing that an antithromboxane agent is able to decrease microalbuminuria, which in this disease is a dual marker of macro- and microangiopathy. Our findings suggest an important role for thromboxane in the pathophysiology of microalbuminuria in diabetes; moreover, we hypothesize that antithromboxane agents may have a place in the treatment/prevention of both macro- and microvascular complications in type 2 diabetic patients.

Topics: Administration, Oral; Albuminuria; Blood Pressure; Cohort Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Double-Blind Method; Exercise; Female; Follow-Up Studies; Heart Rate; Humans; Male; Middle Aged; Phthalic Acids; Platelet Aggregation Inhibitors; Thromboxane B2; Time Factors

To explore the ameliorative effect and mechanism of Panax notoginseng (PNG) and ticlid in treating early diabetic nephropathy (DN).. Fifty-eight patients were divided randomly into two groups, 28 patients of the ticlid group treated with ticlid 250 mg orally, once a day and 30 patients of the PNG group treated with PNG 8 ml in 250 ml of normal saline intravenous drip once a day. The therapeutic effect and relative indexes of the two groups were observed and compared.. After treatment, in both groups, the thromboxane B2 markedly reduced and was more prominent in the ticlid group (P < 0.05), while the 6-keto-prostaglandin F1 alpha increased obviously, so as to cause a significant lowering of T/K ratio, P < 0.01. Levels of urinary albumin, beta 2 microglobulin and blood alpha 1 microglobulin of both groups were lowered significantly, P < 0.01. A significant positive linear correlation was found in the ticlid group between urinary albumin and T/K ratio (r = 0.41, P < 0.01), as well as in blood alpha 1 microglobulin with T/K ratio (r = 0.34, P < 0.05), while it was not found in the PNG group.. Ticlid and PNG were beneficial to resume the balance of T/K and improve microcirculation, reduce whole blood viscosity and decrease urinary albumin so as to retard the progress of DN.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Diabetic Nephropathies; Drugs, Chinese Herbal; Female; Ginsenosides; Humans; Male; Middle Aged; Platelet Aggregation Inhibitors; Saponins; Thromboxane B2; Ticlopidine

To study the effects of Chinese herbal medicine Tangshenkang (TSK) capsule on diabetic nephropathy (DN), 57 patients with DN were randomly divided into two groups, the treated group and the control group, they were treated with TSK capsule and the conventional therapy respectively. There were serious disorders of metabolism in DN patients, that showed the TXB 2/6-keto-PGF1 alpha ratios and lipid peroxidase (LPO) levels were higher than that of healthy people. After 6 weeks treated with TSK capsule the albuminuria levels reduced obviously (decreased 51%), renal plasma flow (RPF) increased, glomerular filtration rate and the LPO levels decreased and a positive correlation was observed between albuminuria levels and TXB 2/6-keto-PGF1 alpha ratios while the clearance rate of creafinin didn't improve significantly. There were no significant difference in the above-mentioned parameters in the control group before and after treatment. These results suggested that TSK capsule possessed a significant effect in improving albuminuria and glomerular function. And the effect of TSK might be due to its adjusting TXB 2/6-keto-PGF1 alpha ratios and its lipid-peroxidation in DN patients.

Topics: 6-Ketoprostaglandin F1 alpha; Adolescent; Adult; Aged; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Drugs, Chinese Herbal; Female; Humans; Lipid Peroxides; Male; Middle Aged; Qi; Thromboxane B2

Studies of nondiabetic renal disease suggest that thromboxane may be an important mediator of abnormal renal function. The role of thromboxane in diabetic nephropathy is not fully understood. We measured in a double-blind, randomized, placebo-controlled crossover study the effect of a thromboxane synthase inhibitor (FCE 22178, 400 mg two or three times per day) on urinary excretion of thromboxane B2 and 6-keto-prostaglandin F1 alpha, glomerular filtration rate (measured as clearance of polyfructosan), effective renal plasma flow (clearance of para-aminohippuric acid), fractional clearances of albumin and immunoglobin G and the reabsorption rate of beta 2-microglobulin in 15 patients with type 1 (insulin-dependent) diabetic nephropathy. In seven additional patients, the effect of the thromboxane synthase inhibitor given as 400 mg twice per day was compared with that of the thromboxane synthase inhibitor given as 400 mg three times per day. FCE 22178 administration caused a significant inhibition in the excretion of urinary thromboxane B2 and 2,3-dinor-thromboxane B2 compared with placebo (12.3 +/- 2.1 vs 24.6 +/- 5.1 ng/gm creatinine, p = 0.006, and 78.5 +/- 20.3 vs 335.5 +/- 84.1 ng/gm creatinine, p = 0.004, respectively) without any compensatory increase of 6-keto- prostaglandin F1 alpha or 2,3-dinor-6-keto-prostaglandin F1 alpha that reflect prostacyclin I2 biosynthesis. Glomerular filtration rate, effective renal plasma flow, renal vascular resistance, and filtration fraction were not significantly different after placebo or thromboxane synthase inhibitor treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Blood Pressure; Creatinine; Diabetic Nephropathies; Double-Blind Method; Drug Administration Schedule; Electrolytes; Female; Glomerular Filtration Rate; Humans; Imidazoles; Immunoglobulin G; Kidney; Male; Middle Aged; Naphthalenes; Proteinuria; Renal Circulation; Thromboxane B2; Thromboxane-A Synthase; Urea

Albumin excretion rates (AER) were measured in 30 insulin-dependent diabetics during a 16-week double-blind, randomised, placebo-controlled study of the specific thromboxane synthetase inhibitor UK-38,485.6 of 15 subjects in the active group had microalbuminuria (defined as mean pretreatment AER 20-150 micrograms/min); in these patients AER fell from 32 +/- 3 micrograms/min to 11 +/- 1 micrograms/min at 8 weeks and 9 +/- 1 micrograms/min at 16 weeks. The AER rose again (to 29 +/- 8 micrograms/min) within 12 weeks of stopping the drug. There was no significant change in the 10 patients with microalbuminuria who received placebo. There was a strong correlation between change from baseline values and the baseline values themselves in the active, but not in the placebo group, and the change from baseline differed significantly between the two groups. There was no change in glycosylated haemoglobin or mean blood glucose levels during the study. In a separate study UK-38,485 caused significant suppression of thromboxane B2 synthesis in diabetic and non-diabetic subjects.

Topics: Adult; Albuminuria; Clinical Trials as Topic; Creatinine; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Double-Blind Method; Female; Humans; Imidazoles; Male; Middle Aged; Oxidoreductases; Thromboxane B2; Thromboxane-A Synthase

Maprotiline is an antidepressant that has been found to cause hypoglycemia. However, the effect of maprotiline on diabetic nephropathy (DN) has not been investigated. Here, we explored the effect of maprotiline on human renal glomerular endothelial cells (HRGECs) in response to high glucose (HG) stimulation. We found that maprotiline attenuated HG-induced oxidative stress in HRGECs with decreased reactive oxygen species production and increased superoxide dismutase activity. Maprotiline repressed the HG-induced expression of cyclooxygenases 2 at both mRNA and protein levels in HRGECs. The increased thromboxane B2 level and decreased 6-keto-prostaglandin F1α level induced by HG were significantly attenuated by maprotiline treatment. Maprotiline also prevented the HG-induced increase in the permeability of HRGECs and the decrease in the zonula occludens-1 expression and downregulated HG-induced increase in the expression of protein kinase C-α (PKC-α) in HRGECs. This protective effect of maprotiline on HG-induced HRGECs dysfunction was abolished by overexpression of PKC-α. In conclusion, maprotiline displayed a protective effect on HG-challenged HRGECs, which was mediated by the regulation of PKC-α. These findings provide further evidence for the potential use of maprotiline for the treatment of DN.

Topics: Cells, Cultured; Diabetic Nephropathies; Endothelial Cells; Glucose; Humans; Kidney Glomerulus; Maprotiline; Oxidative Stress; Prostaglandin-Endoperoxide Synthases; Protein Kinase C-alpha; Reactive Oxygen Species; RNA, Messenger; Superoxide Dismutase; Thromboxane B2

To study the modifying effect and mechanism of Tangshenning Recipe on micro-albuminuria in rats with early diabetic nephropathy (DN).. Male Wistar rats were randomly divided into the normal group (n=8) and model group (n=24). Intraperitoneal injecting of streptozotocin (STZ) plus complete Freund's adjuvant (CFA) was applied once a week for 3 times to induce the DN rats model. Three weeks later, the model group rats were randomly divided into pathologic group (n=8), monopril group (n=8) and Tangshenning Recipe group(n=8) according to the 24 h U-Alb. Each group's renal hemodynamics index and SOD, GSH, MDA in renal tissue were determined by radioimmunoassay (RIA) and colorimetric method respectively.. The levels of plasmatic TXB(2), the ratio of TXB(2) and 6-keto-PGF1alpha, and the CGRP in pathologic group were significantly higher than those in normal group. The levels of plasmatic ET decreased obviously, SOD decreased and MDA increased significantly in the rats' renal tissue of pathologic group. The levels of plasmatic TXB(2), the ratio of TXB(2) and 6-keto-PGF1alpha decreased significantly in both Tangshenning Recipe group and monopril group, and the therapeutic effect of Tangshenning Recipe group was better than that of monopril group. SOD was higher and MDA was lower in Tangshenning Recipe group than that in pathologic group.. The results indicates that Tangshenning Recipe can lower the micro-albuminuria in early DN rats, the mechanism of which probably lies in the modification of glycometabolism, the ratio of TXB(2) and 6-keto-PGF1alpha, the plasmatic CGRP and the renal lipid preoxidation.

Topics: 6-Ketoprostaglandin F1 alpha; Albuminuria; Animals; Diabetic Nephropathies; Disease Models, Animal; Drugs, Chinese Herbal; Glutathione; Male; Malondialdehyde; Phytotherapy; Radioimmunoassay; Random Allocation; Rats; Rats, Wistar; Superoxide Dismutase; Thromboxane B2; Treatment Outcome

To elucidate the relationship between the thromboxane A2/prostacyclin (TXA2/PGI2) ratio and diabetic complications, the levels of 11-dehydro-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin F1alpha, the urinary metabolites of thromboxane A2 and prostacyclin, were measured in diabetics by gas chromatography/selected ion monitoring. We compared the TXA2/PGI2 ratio in healthy volunteers and diabetics. The TXA2/PGI2 ratio of diabetics was significantly higher than that of healthy volunteers and we could reconfirm the hypercoagulable condition in diabetics. We also investigated the difference of TXA2/PGI2 levels in diabetics with retinopathy and neuropathy. The TXA2/PGI2 ratio of diabetics with retinopathy showed significantly higher level than without retinopathy. However, the TXA2/PGI2 ratio of diabetics with neuropathy was the same as without neuropathy. These results suggest that the TXA2/PGI2 ratio reflects the pathological conditions of diabetes, especially the change of vasculature. The monitoring and improvement of TXA2/PGI2 ratio could be useful for the prevention of diabetic vascular complications.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Chromatography, Gas; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Neuropathies; Epoprostenol; Female; Humans; Male; Thromboxane B2

To determine the pathogenic role of serotonin (5-HT), we investigated 5-HT metabolism in undergoing hemodialysis (HD). Mean value of platelet 5-HT in patients undergoing HD was significantly lower than that of normal controls (0.22 + or - 0.16 pmol/10(5) platelets versus 0.35 + or - 0.13 pmol/10(5) platelets, p <0.02). While platelet uptake of 5-HT in normal controls reached a plateau in each experiment after incubation with authentic 5-HT for 60 min, platelet uptake of 5-HT in patients undergoing HD reached various levels. We found significantly lower platelet 5-HT levels in patients with diabetes mellitus (DM) after HD compared with those in patients with chronic glomerulonephritis (p <0.05). The pathogenic role of serotonergic amplifying mechanism especially in patients with DM should be investigated. Second, we investigated plasma 11-dehydro-thromboxane B2 (11-DTXB2) levels in patients undergoing HD. Mean level of plasma 11-DTXB2 concentration in patients after HD was significantly higher than in patients before HD (32.8 + or - 17.0 pg/ml versus 23.7 + or - 7.2 pg/ml, p <0.02). Increased plasma levels of 11-DTXB2 after HD were regarded as an indication of hypercoagulation. Our results provide evidence that several factors such as hypercoagulation, heparin, 5-HT uptake of platelet, or causal diseases of renal failure could be responsible for the lower platelet 5-HT levels in patients undergoing HD.

Topics: Adult; Aged; Blood Platelets; Case-Control Studies; Chromatography, High Pressure Liquid; Diabetic Nephropathies; Female; Glomerulonephritis; Humans; Kidney Failure, Chronic; Male; Middle Aged; Renal Dialysis; Serotonin; Thromboxane B2

Wistar rats (4-week-old) were administered with streptozotocin (45 mg/kg) through tail veins. After 3 months, diabetic rats were divided into 2 groups. One group (EPA group, n = 16) was fed a lipid-free diet (90%, w/w) plus lard (8%) and 90% pure eicosapentaenoic acid ethyl ester (2%) for 6 months. The other group (control group, n = 16) was fed in the same way except that eicosapentaenoic acid ethyl ester was replaced by safflower oil. Twenty-four-hour urine was collected just before starting the experimental diets and during the 6-month experimental period at monthly intervals. There were no differences in food intake and body weight between the two groups throughout the experiment. The mean microalbuminuria of the EPA group became significantly lower than that of the control group after 4 months on the diets through the end of the study (6 months). The mean microalbuminuria levels at the end of the study were 1.38 mg/day in the EPA group (n = 9) and 5.19 mg/day in the control group (n = 6) (p < 0.01). Eicosapentaenoic acid administration might retard the progression of diabetic nephropathy by reducing microalbuminuria.

Topics: 6-Ketoprostaglandin F1 alpha; Albuminuria; Animals; Blood Glucose; Blood Pressure; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Eating; Eicosapentaenoic Acid; Fatty Acids; Kidney; Lipids; Male; Organ Size; Rats; Rats, Wistar; Thromboxane B2; Weight Gain

Spontaneously hypertensive rats (SHR) were injected with streptozotocin (STZ-SHR) to induce diabetes. The effect of DP-1904, a thromboxane A2 synthetase inhibitor, on diabetic nephropathy was then studied by administering it for 5 months (1 or 10 mg/kg). DP-1904 did not affect renal 6-keto prostaglandin (PG)F1 alpha production in STZ-SHR, but markedly inhibited renal thromboxane (TX) B2 production, so that the 6-keto PGF1 alpha/TXB2 ratio was significantly increased (P less than 0.05). STZ-SHR showed significant uraemia and proteinuria, plus increases in urinary gamma-glutamyl-transpeptidase and urinary N-acetyl-beta-glucosaminidase. DP-1904 significantly decreased (P less than 0.01) the urinary changes. STZ-SHR also showed an increase in mesangial periodic acid-Schiff-positive substance and in relative renal weight, both of which were significantly inhibited by DP-1904 (P less than 0.05). Thus, DP-1904 inhibited both TXB2 production and the progression of renal damage in STZ-SHR.

Topics: Acetylglucosaminidase; Animals; Blood Pressure; Diabetes Mellitus, Experimental; Diabetic Nephropathies; gamma-Glutamyltransferase; Heart Rate; Hypertension; Imidazoles; Kidney; Prostaglandins; Proteinuria; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Tetrahydronaphthalenes; Thromboxane B2; Thromboxane-A Synthase

To investigate the possible relevance of free radicals and prostanoids to the mode of initiation and/or evolution of microangiopathy in diabetes mellitus, we measured serum lipid peroxides (LPO), an accepted index of intravascular free radicals, and plasma 11-dehydrothromboxane B2 (11-dehydro-TXB2), a stable metabolite of vasoactive thromboxane A2 released from platelets, in 95 patients with normolipidemic type 2 (non-insulin-dependent) diabetes mellitus at different stages of the disease. In general, either LPO or 11-dehydro-TXB2 was significantly greater in the patients, as a group, than in the matched controls (3.82 vs. 2.65 nmol/ml, P < 0.01 for LPO; and 17.3 vs. 5.8 pg/ml, P < 0.01 for 11-dehydro-TXB2). In patients, both LPO and 11-dehydro-TXB2 increased according to the severity of their diabetic retinopathy. A highly significant positive correlation existed between the LPO values and 11-dehydro-TXB2 in the patients (r = 0.64, P < 0.0001), while there was no such relationship in the controls (r = 0.18, P = NS). No difference in serum levels of apolipoproteins A-I, A-II, B, C-II, C-III, or E was observed between the patients and controls. Short-term glycemic control (25 cal/kg of standardized body weight/day, for 8 weeks) resulted in a small but significant reduction in LPO (4.2 vs. 4.6 nmol/ml, control; P < 0.05) without alteration in 11-dehydro-TXB2. There was a tendency towards deterioration in LPO according to the improvement in glycemic control. These results appear consistent with the view that, in addition to LPO, the release of TXA2 from activated platelet in the human circulation could be an important factor for the initiation and/or evolution of microangiopathy in diabetic patients even when they are not apparently hyperlipidemic. Further, the results of the present study emphasize the notion that more tight control of serum lipids is worthy of serious consideration in preventing the advance of diabetic microangiopathy.

Topics: Aged; Apolipoproteins; Biomarkers; Blood Glucose; Cholesterol; Cholesterol, HDL; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Retinopathy; Female; Free Radicals; Glycated Hemoglobin; Humans; Lipid Peroxidation; Lipid Peroxides; Male; Middle Aged; Reference Values; Thromboxane B2; Triglycerides

Serum creatinine, immunoreactive serum and urine beta 2-microglobulin, plasma and urine thromboglobulin, plasma thromboxane-B2 levels and daily protein excretion were determined in 61 insulin-treated diabetic patients, comparing the different patient groups (complication free, nephropathy without and with azotaemia) with control subjects. In the groups of diabetic patients, plasma and urine beta-thromboglobulin (BTG) and plasma thromboxane-B2 levels were higher than in the controls. There was a significant positive correlation between urine BTG and beta 2-microglobulin in the group without complication, and between the plasma BTG and beta 2-microglobulin, and plasma BTG and thromboxane levels in the diabetic group with azotaemia. In contrast to some previous assumptions, the increased level of plasma BTG reflects a real platelet hyperactivation in patients with diabetic nephropathy. At the same time, urine BTG also increases. Determination of urine BTG is more simple with less possibility of methodological error.

Topics: Adult; beta 2-Microglobulin; beta-Thromboglobulin; Biomarkers; Creatinine; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Humans; Middle Aged; Platelet Activation; Thromboxane B2

Haemostatic activation was measured in patients with either non-diabetic chronic renal failure (CRF) or diabetic nephropathy. We have investigated the relationship between these haemostatic markers and the rate of progression of renal failure. When compared with age- and sex-matched healthy controls, both patient groups showed significantly elevated plasma concentrations of D dimer, von Willebrand factor antigen (vWFAg), and C-reactive protein (CRP) (all P less than 0.001), as well as an increase in spontaneous platelet aggregation (P less than 0.01). Plasma concentration of platelet factor 4 was slightly but not significantly increased. Serum thromboxane was subnormal (P less than 0.01). Multiple regression analysis showed that in non-diabetic CRF proteinuria and serum TxB2 were independently related to the rate of progression of renal failure; in diabetic nephropathy proteinuria and vWFAg were independently related to the rate of progression. In both groups the relationship was stronger with proteinuria (standardised regression coefficients 0.56 and 0.45 respectively) than with serum TxB2 (0.29) or with vWFAg (0.37). We have found haemostatic activation in both non-diabetic and diabetic progressive renal failure. Proteinuria, and also in this study serum TxB2 and vWFAg, appear to be determining factors in the progression of renal failure, and their measurement may have prognostic value.

Topics: Adolescent; Adult; Aged; Antigens; Diabetic Nephropathies; Female; Glomerulosclerosis, Focal Segmental; Hemostasis; Humans; Kidney; Kidney Failure, Chronic; Male; Middle Aged; Platelet Activation; Proteinuria; Thromboxane B2; von Willebrand Factor

Renal hypertrophy occurs early in the natural history of human and experimental diabetes and may be a manifestation of the same pathophysiological process which ultimately results in diabetic nephropathy. The precise biological events which stimulate and regulate this growth process remain incompletely understood. We postulated that renal eicosanoids contribute to the development of renal hypertrophy in diabetes. We elected to test the effects of suppression of dienoic eicosanoid metabolism (arachidonic acid metabolism) on renal hypertrophy in diabetic rats by feeding fish oil. Diabetic rats fed fish oil had markedly reduced insulin requirements compared to control rats pair-fed a beef tallow-rich diet. The concentrations of prostaglandin E2, 6-keto-prostaglandin F1 alpha, and thromboxane B2 were depressed in the renal cortex of diabetic rats fed fish oil. This alteration in eicosanoid metabolism was associated with a substantial enhancement of diabetic renal hypertrophy. These results indicate that dietary fish oil has profound effects on renal eicosanoid metabolism in experimental diabetes and that these autocoids may participate in the biological events which regulate diabetic renal hypertrophy.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Dietary Fats; DNA; Fish Oils; Glycated Hemoglobin; Hypertrophy; Insulin; Kidney; Male; Prostaglandins; Proteins; Rats; RNA; Thromboxane B2

To examine the effects of endogenous thromboxane A2 on the development of diabetic nephropathy, we administered OKY-046, an inhibitor of thromboxane synthesis, to streptozotocin-induced diabetic rats. Animals were divided into three groups; nondiabetic control, diabetic, and diabetic with OKY-046, and were sacrificed 16 weeks after experimental procedures. The chronic oral administration of OKY-046 to diabetic rats significantly decreased plasma and urinary thromboxane B2 levels. Urinary protein excretion and serum glucose levels were significantly lower in the OKY-046-treated diabetic rats than in the untreated diabetics (60.8 +/- 23.2 vs. 94.1 +/- 33.4 mg/day in the 16th week, p less than 0.05 and 424.4 +/- 93.3 vs. 614.4 +/- 102.3 mg/dl in the 16th week, p less than 0.01, respectively). Platelet aggregation was inhibited by OKY-046. Blood urea nitrogen was unaffected. Ultrastructural examination revealed that the thickness of glomerular basement membrane was markedly thinner in the OKY-046-treated diabetic rats than in the untreated diabetics (197.4 +/- 29.6 vs. 288.6 +/- 46.9 nm, p less than 0.01). These results suggest that thromboxane A2 may play an important role in the development and progression of diabetic nephropathy in rats.

Topics: 6-Ketoprostaglandin F1 alpha; Administration, Oral; Animals; Blood Glucose; Blood Pressure; Blood Urea Nitrogen; Body Weight; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Insulin; Kidney; Male; Methacrylates; Microscopy, Electron; Platelet Aggregation; Proteinuria; Rats; Rats, Inbred Strains; Thromboxane A2; Thromboxane B2; Thromboxane-A Synthase

Recently the beneficial effects of captopril (angiotensin-converting-enzyme inhibitor) on diabetic nephropathy, especially proteinuria, have been reported by some investigators. The mechanism whereby proteinuria is reduced, however, have not been clarified yet. The present study was undertaken to evaluate the effects of captopril on urinary albumin excretion in relation to urinary prostaglandins (PGs) excretion in patients with non-insulin-dependent diabetes mellitus (NIDDM). Captopril (37.5 mg/day) was orally administered to 13 diabetic patients for an eight-week period. A single administration of captopril (12.5 mg) was performed in the same patients. The spot urine samples were collected in the early morning and 2 hr after the single administration of captopril. The albumin index (mg/gram-creatinine) was markedly decreased in eight patients (Group A) within four weeks, but no decrease was found in five patients (Group B). Furthermore, in Group A, by the single administration of captopril urinary excretions of 6-keto-PCF1 alpha (a stable metabolite of PGI2) and PGE2 were significantly (p less than 0.05) increased while urinary TXB2 (a stable metabolite of TXA2) excretion did not change significantly. The urinary 6-keto-PGF1 alpha/TXB2 ratio, which is significantly (p less than 0.05) low in diabetic patients was significantly (p less than 0.01) increased up to the normal value in Group A. In Group B, however, there were no significant changes in urinary PGs excretion. These results suggest that captopril enhances the production of intrarenal vasodilatory PGs such as PGI2 and PGE2, which may be deeply involved in the reduction of intraglomerular capillary pressure and urinary protein excretion in diabetic patients.

Topics: 6-Ketoprostaglandin F1 alpha; Albuminuria; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Retinopathy; Female; Humans; Male; Middle Aged; Prostaglandins; Thromboxane B2

The value of high polyunsaturated fatty acid (PUFA) diets in preventing diabetic nephropathy in rats was studied. Diabetes was induced by intravenous injection of streptozotocin (SZ), 65 mg/kg. Rats were divided in four groups fed diets containing 11% fat for 38 weeks. Dietary fat derived from four sources: beef tallow (BT; rich in saturated fatty acids), evening primrose oil (EPO; rich in gamma linolenic [GLA] and linoleic acids [LA]), safflower oil (SO; rich in LA), and fish oil (FO; rich in eicosapentaenoic [EPA] and docosahexaenoic [DHA] acids). Ultralente insulin was administered every other day to maintain the blood glucose levels between 11.1 and 22.2 mmol/L (200 and 400 mg/dL). The diets prepared with EPO and SO had a clear beneficial effect on proteinuria, glomerular sclerosis, and tubular abnormalities, as compared with BT. Both diets also increased the ratio of renal cortical production of 6-keto-PGF1 alpha to thromboxane B2 (TXB2), the stable metabolites of PGI2 and TXA2, respectively. They did not induce significant changes in plasma lipid composition. The FO diet did not have an effect on renal disease, but decreased plasma lipids and inhibited eicosanoid synthesis by platelets and kidney cortex. FO feeding was associated with a lowered 6-keto-PGF1 alpha/TXB2 ratio. It is concluded that high LA diets are protective in this model of diabetic nephropathy. The effect may be secondary to modifications of the eicosanoid balance. Diets containing FO have a beneficial effect on plasma lipids in this model.

Topics: Animals; Blood Platelets; Calcium; Cholesterol; Creatinine; Diabetic Nephropathies; Dietary Fats, Unsaturated; Eicosanoids; Female; Kidney; Linoleic Acids; Phospholipids; Phosphorus; Proteinuria; Rats; Rats, Inbred Strains; Serum Albumin; Thromboxane B2; Triglycerides

We prospectively evaluated a platelet-inhibitor regimen of dipyridamole and aspirin in 28 patients with insulin-dependent diabetes mellitus and well-established nephropathy. After a mean treatment period of 4.3 years, iothalamate clearance (Ciot) was reasonably well maintained and urinary protein excretion was reduced in 7 patients (25%), whereas 21 (75%) had progressive nephropathy. Analysis of outcome revealed that all 7 patients with stable nephropathy and 9 of the 21 with progressive disease had baseline Ciot values that exceeded 50 ml/min per 1.73 m2. Shortened platelet survival improved after 3 months of treatment, and the distribution between patients who had stable and those who had progressive disease was approximately equal. Mean changes in fasting plasma glucose level, glycosylated hemoglobin, and blood pressure did not differ between these two groups. In a short-term protocol, urinary protein and thromboxane B2 significantly declined, whereas variable urinary levels of prostaglandin E2, 6-ketoprostaglandin F1 alpha, and Ciot did not change after 3 months of treatment with dipyridamole and aspirin. These findings suggest that treatment with dipyridamole and aspirin may stabilize renal function by reducing platelet hypersensitivity and production of thromboxanes by platelet or renal tissue (or both). In turn, constrictor activity in the glomerular vessels, mesangial contractility, and glomerular membrane permeability are decreased. These data also add evidence in support of a role for thromboxane A2 in the pathogenesis of experimental and human glomerular disease.

Topics: Adult; Aspirin; Blood Platelets; Cell Survival; Creatinine; Diabetic Nephropathies; Dipyridamole; Drug Therapy, Combination; Female; Humans; Iothalamic Acid; Male; Middle Aged; Platelet Aggregation Inhibitors; Prospective Studies; Proteinuria; Thromboxane B2

Coagulation parameters, platelet aggregation, and thromboxane production as well as metabolic parameters were measured in 31 diabetic patients, 12 without and 19 with clinically manifest late complications, and in 14 healthy control subjects. Spontaneous in vitro aggregation as well as ADP, collagen, and arachidonic acid induced aggregation were higher in both groups of diabetic patients, without an increase in thromboxane B2 production. In diabetic patients with late complications an increase in fibrinogen, fibrinogen cyanogen bromide peptide, factor VIII related antigen, C1-esterase inhibitor, and antithrombin III was observed in comparison to healthy subjects. Fibrinogen, C1-esterase inhibitor, and factor VIII related antigen were already elevated in diabetic patients without clinically manifest late vascular complications. No strict correlations were found between serum glucose, glycosylated hemoglobin, and glycosylated albumin, on the one hand, and coagulation promoting or inhibiting factors, aggregation or thromboxane B2 production, on the other, in either control or diabetic subjects. Also no correlations existed between the coagulation parameters and the aggregation results. In vitro incubation of pooled normal plasma with different glucose concentrations had no influence on the methods by which the coagulation parameters were measured. These data indicate that rather early in the diabetic state many changes take place in different phases of the thrombostatic process, all resulting in an increased hemostatic diathesis.

Topics: Adult; Antithrombin III; Blood Coagulation Tests; Blood Glucose; Complement C1 Inactivator Proteins; Diabetes Mellitus; Diabetic Nephropathies; Diabetic Neuropathies; Diabetic Retinopathy; Fibrinogen; Humans; Platelet Aggregation; Thromboxane B2