抄録
Prostaglandins (PGs) are widely distributed in biological organs, and plays an important role as cellular mediating factor.
In endocrinological organs they have been reported to be involved in hormone secretion. As for insulin secretion, however, the consistent effect of PGs on somatostatin release have not been reported to our knowledge.
Therefore, 20 islets isolated from Wistar male rats, 250-300g in body weight, were perifused to evaluate a role of PGs in pancreatic hormone release.
The standard perifusate was Krebs-Henseleit bicarbonate buffer, pH7.4, containing 0.25% bovine serum albumin and 8.3mM glucose.
Perifusion speed was 0.5ml/min. and the perifusate was collected in a test tube every 2 minutes.
In the experiment, the islets was perifused with PGE1 and PGE2 of 10-7M to 10-5M added in the standard medium for 14 minutes each.
PGE1 and PGE2 at the present concentration did not change insulin secretion pattern of the control.
Sum of insulin secretion for 14 minutes was not affected by these PGs also.
Somatostatin secretion was not influenced by the PGE1 and E2 as well.
In order to evaluate a role of endoginous PGs in insulin secretion sodium salicylate, which inhibits PG synthesis, was added in the standard perifusate.
Insulin secretion was by 50-60% decreased by this treatment.
These supression was recovered to the level prior to the administration of sodium salicylate by the addition of 10-6M PGE1 and PGE2.
Therefore, the endogenous PGE1 and PGE2 might be involved in insulin secretion, although a role of endogenous PGs in somatostatin release was not clarified by the present investigations.
