Abstract
(A) Diabetes was induced in 7-week-old female Sprague-Dawley rats by injection with streptozotocin, and the eicosanoid (PG) production by mesenteric vascular bed perfusion examined. (1) The levels of 6-keto-PGF1α (6KF) and thromboxane B2 (TxB2) increased and the 6KF/TxB2 ratio decreased significantly in diabetic rats compared with non-diabetic control rats. (2) PG production decreased in the diabetic rats with daily insulin treatment compared with untreated diabetic control rats. (3) The levels of TxB2 increased and the 6KF/TxB2 ratio decreased when the glucose concentration in buffer was adjusted to 500 mg/dl. (4) The PG production of diabetic rats was not changed significantly when insulin was added to the buffer. (5) Analysis of the free fatty acid composition of mesenteric vascular tissue showed that 16: 0, 16: 1 and 18: 1n-6 were decreased, while 18: 0, 18: 3n-6, 20: 3n-6, 22: 5n-3 and 22: 6n-3 increased in lhe diabetic rats compared with non-diabetic control rats.
An increase in the production of PG was thus demonstrated in diabetic rats. These observations also suggested that the increased PG production might be associated with insulin deficiency and/or hyperglycemia.
