U-73122 does not specifically inhibit phospholipase C in rat pancreatic islets and insulin-secreting beta-cell lines.

Publication/Presentation Date

1-1-1994

Abstract

Phospholipase C is activated in insulin secretion by islets of Langerhans and insulin-secreting beta-cells such as RINm5F and beta-TC3. We have examined the effects of the aminosteroid U-73122, a phospholipase C inhibitor, on insulin secretion and phospholipase C activation. U-73122 slightly inhibited glucose-induced insulin secretion from islets, but this effect was not specific since the structural "inactive" analogue U-73343 also inhibited insulin secretion. Likewise, in RINm5F cells, U-73122 did not inhibit glyceraldehyde-induced insulin secretion. Phospholipase C activity was assessed as the accumulation of inositol-1,4,5-trisphosphate (Ins(1,4,5)P3) measured with a competitive binding assay: U-73122 failed to inhibit glucose-induced increase in Ins(1,4,5)P3. Similarly, when the effects of U-73122 and U-73343 were measured on [3H]phosphatidylinositol hydrolysis of islets, both compounds caused a slight, non-specific inhibition of phospholipase C activity. These observations suggest that U-73122 does not specifically inhibit phospholipase C in insulin-secreting cells.

Volume

54

Issue

8

First Page

107

Last Page

112

ISSN

0024-3205

Disciplines

Medicine and Health Sciences | Pediatrics

PubMedID

8107526

Department(s)

Department of Pediatrics

Document Type

Article

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