6-ketoprostaglandin-f1-alpha and Diabetic-Neuropathies

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

The effect of a prostacyclin analog, beraprost sodium, on the electroretinogram, motor nerve conduction velocity, and nerve blood flow was determined in rats with streptozotocin-induced diabetes and was compared with the effect of insulin. Beraprost sodium (0.01 mg x kg-1 x day-1 for 8 weeks) significantly shortened the peak latency of the electroretinogram b-wave, increased tail nerve conduction velocity, and increased sciatic nerve blood flow in diabetic rats (P < 0.0003, 0.0001, and 0.0001 vs. untreated diabetic rats, respectively). This was accompanied by a significant increase in the 6-keto-prostaglandin F1alpha content of the thoracic aorta and a marked increase in the cAMP content of the sciatic nerve. Beraprost sodium had no effect on the sorbitol and fructose contents of the sciatic nerve and retina, but insulin (8-10 U/day) significantly reduced both parameters. These findings suggest that beraprost sodium may be useful for prevention of vascular and neural dysfunction in the retina and peripheral nerve.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Aorta, Thoracic; Cyclic AMP; Diabetes Mellitus, Experimental; Diabetic Neuropathies; Diabetic Retinopathy; Electroretinography; Epoprostenol; Insulin; Male; Neural Conduction; Rats; Rats, Wistar; Retina; Sciatic Nerve

The abnormalities underlying diabetic neuropathy appear to be multiple and involve metabolic neuronal and vasomediated defects. The accumulation of long-chain fatty acids and impaired beta-oxidation due to deficiencies in carnitine and/or its esterified derivatives, such as acetyl-L-carnitine, may have deleterious effects. In the present study, we examined, in the diabetic bio-breeding Worcester rat, the short- and long-term effects of acetyl-L-carnitine administration on peripheral nerve polyols, myoinositol, Na+/K+ -ATPase, vasoactive prostaglandins, nerve conduction velocity, and pathologic changes. Short-term prevention (4 mo) with acetyl-L-carnitine had no effects on nerve polyols, but corrected the Na+/K+ -ATPase defect and was associated with 63% prevention of the nerve conduction defect and complete prevention of structural changes. Long-term prevention (8 mo) and intervention (from 4 to 8 mo) with acetyl-L-carnitine treatment normalized nerve PGE(1) whereas 6-keto PGF(1-alpha) and PGE(2) were unaffected. In the prevention study, the conduction defect was 73% prevented and structural abnormalities attenuated. Intervention with acetyl-L-carnitine resulted in 76% recovery of the conduction defect and corrected neuropathologic changes characteristic of 4-mo diabetic rats. Acetyl-L-carnitine treatment promoted nerve fiber regeneration, which was increased two-fold compared to nontreated diabetic rats. These results demonstrate that acetyl-L-carnitine has a preventive effect on the acute Na+/- K+_ATPase defect and a preventive and corrective effect on PGE1 in chronically diabetic nerve associated with improvements of nerve conduction velocity and pathologic changes.

Topics: 6-Ketoprostaglandin F1 alpha; Acetylcarnitine; Alprostadil; Animals; Diabetic Neuropathies; Dinoprostone; Fructose; Inositol; Male; Neural Conduction; Rats; Rats, Inbred BB; Sciatic Nerve; Sodium-Potassium-Exchanging ATPase; Sorbitol; Time Factors

We studied the effect of a thromboxane A2 (TXA2) dual blocker KDI-792 on skin blood flow as well as on the peripheral nerve function of nine diabetics with neuropathy. After administration of KDI-792, there was no change in urinary TXB2; however, urinary 6-keto-prostaglandin (PG) F1 alpha increased significantly. Nerve conduction velocity (NCV) and vibration perception threshold (VT) in the four extremities improved significantly, as did deep skin temperature and skin blood flow. The degree of improvement in sensory NCV in the lower extremities correlated significantly with that of deep skin temperature in the toes and the degree of improvement of VT in the lower extremities correlated well with that of deep skin temperature in the soles and of skin blood flow in the toes. Based on these findings, treatment of diabetic neuropathy with a TXA2 dual blocker appears to increase PGI2 production, improving blood flow, and resulting in improvement of nerve functions.

Topics: 6-Ketoprostaglandin F1 alpha; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Enzyme Inhibitors; Extremities; Female; Humans; Male; Middle Aged; Neural Conduction; Perception; Pyridines; Pyrrolidines; Skin; Skin Temperature; Thromboxane A2; Thromboxane B2; Toes; Vibration

On the basis of vascular involvement, an open clinical trial was performed to determine whether or not the antithrombotic drug cilostazol (6-[4-(1-cyclohexyl-1H-tetrazol-5-yl) butoxy]-3,4-dihydro-2(1H)-quinolinone, OPC-13013, Pletaal, CAS 73963-72-1) applied as a single 100 mg tablet increases peripheral blood flow and prevents diabetic neuropathy in 30 patients with non-insulin dependent diabetes mellitus. The hemodynamic effects of this drug on the a. dorsalis pedis were examined using a new real-time two-dimensional Doppler echography. 1 h after oral administration of cilostazol, the cross-sectional area of the a. dorsalis pedis significantly increased from 2.2 +/- 0.2 to 2.9 +/- 0.3 mm2 (p less than 0.05). Also, the a. dorsalis pedis blood flow index significantly increased from 16 +/- 1 to 31 +/- 4 (p less than 0.05). Cilostazol did not affect plasma glucose level (from 213 +/- 14 to 198 +/- 15 mg/dl), but slightly plasma ratio of 6-keto PGF1a to TXB2 (from 0.71 +/- 0.09 to 0.83 +/- 0.12). These effects of cilostazol might ameliorate diabetic neuropathy by improving blood flow and preventing nerve tissue ischemia.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Aged; Arteries; Blood Glucose; Cilostazol; Diabetic Neuropathies; Female; Hemodynamics; Humans; Male; Middle Aged; Tetrazoles; Thromboxane B2; Vasodilator Agents

1. Diurnal patterns of urine output and sodium and potassium excretion were studied in 10 diabetic patients with and 10 without autonomic neuropathy, and in 10 normal subjects. 2. The diurnal patterns of excretion in the diabetic patients with autonomic neuropathy differed significantly from the two other groups, as a smaller proportion of the 24 h output of urine, sodium and potassium was excreted during the day and a larger proportion was excreted at night. 3. Similar changes were noted in the diurnal patterns of urinary kallikrein excretion in diabetic patients with autonomic neuropathy, and urinary kallikrein output correlated significantly with urine volume but not with urinary sodium excretion. 4. The diurnal patterns of excretion of urinary prostaglandin E2 and 6-keto-PGF1 alpha were not significantly different in diabetic patients with autonomic neuropathy. 5. Nocturia was a common complaint in this group, and the number of nocturnal voidings correlated with night urine volume. There was no evidence of premature bladder emptying. 6. The changes observed in the day/night urine output and sodium excretion could not be explained by glycosuria, insulin regimens, impaired renal function or abnormal diurnal prostaglandin excretion; their possible relevance to the diurnal changes of urinary kallikrein excretion is discussed.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Autonomic Nervous System Diseases; Circadian Rhythm; Creatinine; Diabetes Mellitus; Diabetic Neuropathies; Dinoprostone; Female; Glycosuria; Humans; Kallikreins; Male; Middle Aged; Potassium; Prostaglandins E; Sodium

The relationship between diabetic neuropathy on the one hand and microangiopathy and arteriosclerosis on the other was studied by determining plasma 6-keto-prostaglandin F1 alpha (PGF1 alpha) and plasma thromboxane B2 (TXB2) in diabetics with neuropathy. The subjects were 13 patients with insulin independent diabetes mellitus with polyneuropathy (DN+ group), 9 cases which had no neuropathy (DN- group) and 6 control cases. The patients with severe retinopathy, nephropathy and hypertension were excluded. Plasma 6-keto-PGF1 alpha and plasma TXB2 concentration were determined by radioimmunoassay. The motor neuron conduction velocity (M.C.V.) was measured through the tibial nerve in all diabetics. Plasma 6-keto-PGF1 alpha was 116.3 +/- 4.2 pg/ml (mean +/- SE) in the DN+ group and 139.9 +/- 3.0 in the DN- group, each group showing a significant fall over the control with 150.8 +/- 4.5. Plasma 6-keto-PGF1 alpha in the DN+ group showed a significant decrease in comparison with that in the DN- group. As to plasma TXB2, there was no significant difference among the three groups. The M.C.V. fell off significantly in the DN+ group with 52.9 +/- 3.2 m/sec. Furthermore, a significant positive correlation was observed between M.C.V. and plasma 6-keto-PGF1 alpha. The following is the summary of these results. A decrease in plasma 6-keto-PGF1 alpha was observed in diabetics with polyneuropathy. A decrease in the production of prostacyclin (PGI2) due to impairment of vascular endothelium in the nerve tissue was surmised. The decrease in plasma 6-keto-PGF1 alpha presumably stimulates the activity of platelet agglutination and causes an ischemic change in the nerve tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Humans; Middle Aged; Motor Neurons; Neural Conduction; Thromboxane B2