thromboxane-b2 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

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

The effects of the prostacyclin analog beraprost sodium on motor nerve function and nerve blood-flow were examined in streptozotocin-induced diabetic rats. Oral administration of beraprost sodium 0.1 mg/kg/day for 8 wks significantly (P < 0.001) improved caudal motor nerve conduction velocity and sciatic nerve blood-flow, both of which are impaired in diabetic rats. Beraprost sodium did not affect glucose, sorbitol, or fructose levels in the sciatic nerve. However, a decreased content of cyclic AMP in the sciatic nerve and higher level of thromboxane B2 in the thoracic aorta of diabetic rats, as compared with those in normal rats, were reversed by the treatment with beraprost sodium (P < 0.01). Results suggest that beraprost sodium may have value in treating diabetic neuropathy, mainly by improving endoneurial blood-flow.

Topics: Animals; Aorta, Thoracic; Blood Glucose; Cyclic AMP; Diabetes Mellitus, Experimental; Diabetic Neuropathies; Epoprostenol; Fructose; Glucose; Male; Motor Neurons; Muscle, Smooth, Vascular; Neural Conduction; Platelet Aggregation Inhibitors; Rats; Rats, Wistar; Reference Values; Regional Blood Flow; Sciatic Nerve; Sorbitol; Thromboxane B2

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

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

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