[Evaluation of plasma 6-keto-prostaglandin F1 alpha and thromboxane B2 in diabetic neuropathy].

: 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)