[Change in enzyme activities caused by the concentration of cerebrospinal fluid]

Increased production of platelet thromboxane B2 in non-insulin-dependent diabetes. Relationship to vascular complications

Platelet thromboxane B2 production was studied in forty-seven non-insulin-dependent diabetics by incubating platelets with increasing concentrations of arachidonic acid. In comparison with thirty-two healthy subjects, diabetics showed increased thromboxane B2 production at 0.7 mmol/l (mean: 236 pmol/10(8) platelets, SEM 201-277; v. 135, 105-174; P less than 0.05) and at 1.0 mmol/l (673, 613-739; v. 405, 377-486, P less than 0.01) but not at 0.5 mmol/l. Patients were subdivided according to the presence or absence of vascular complications. Patients without microangiopathy showed significantly greater thromboxane B2 production than healthy subjects at all the arachidonic-acid concentrations (P less than 0.02 or less). Patients with microangiopathy had platelet thromboxane production similar to that observed in healthy subjects at all the arachidonic-acid concentrations (P greater than 0.30) but significantly lower than that of non-microangiopathic patients at 0.5 (P less than 0.01) and at 0.7 mmol/l arachidonic acid (P less than 0.05). These results indicate that non-insulin-dependent diabetics have increased production of platelet thromboxane B2 only when they do not have microvascular complications.