ARACHIDONIC-ACID METABOLISM AND URINARY-EXCRETION OF PROSTAGLANDINS AND THROMBOXANE IN RATS WITH EXPERIMENTAL DIABETES-MELLITUS

  • 1 January 1985
    • journal article
    • research article
    • Vol. 234  (1) , 211-216
Abstract
Urinary prostaglandins (PGs) and thromboxane excretion, measured by radioimmunoassay, were examined in male Wistar rats made diabetic with streptozotocin, 70 mg/kg. In addition, immunoreactive (i) 6-keto-prostaglandin F1.alpha. (6-keto-PGF1.alpha.) production by aortic rings was studied as well as conversion of [14C]arachidonic acid (AA) by aortic rings, polymorphonuclear leukocytes and macrophages isolated from diabetic and age-matched control rats. The profile of urinary eicosanoid excretion changed after induction of diabetes. iPGF2.alpha. excretion transiently increased, reaching a peak at 7 days and declining to control values by 48 days. iPGE2 excretion declined with time after induction of diabetes while marked increases in i thromboxane B2 and i6-keto-PGF1.alpha. excretion occurred within 48 h and were maintained for the duration of the study, up to 176 days. Serum i thromboxane B2 levels were similar in control and diabetic rats. Formation of i6-keto-PGF1.alpha. by aortic rings obtained from diabetic rats was approximately one-half that of aortic rings from control rats. Similarly, conversion of [14C]AA revealed a diminished capacity of aortic rings from diabetic rats to synthesize prostacyclin (PGI2) measured as 6-keto-PGF1.alpha.. Conversion of [14C]AA by polymorphonuclear leukocytes and macrophages obtained from diabetic rats did not differ from those obtained from control rats. Experimental diabetes mellitus is accompanied by temporal alterations in AA metabolism, the functional significance of which is unknown at this time.