Referenced in: none

Automatically associated channels: TRP , TRPM , TRPM5

Title: Role of transient receptor potential melastatin-like subtype 5 channel in insulin secretion from rat β-cells.

Authors: Kalaiselvan Krishnan, Zuheng Ma, Anneli Björklund, Md Shahidul Islam

Journal, date & volume: Pancreas, 2014 May , 43, 597-604

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/24632551

Abstract
Several studies have reported that the transient receptor potential melastatin-like subtype 5 (TRPM5) channel, a Ca(2+)-activated monovalent cation channel, is involved in the stimulus-secretion coupling in the mouse pancreatic β-cells. We have studied the role of the TRPM5 channel in regulating insulin secretion and cytoplasmic free Ca(2+) concentration ([Ca(2+)](i)) in the rat β-cells by using triphenylphosphine oxide, a selective inhibitor of the channel.Insulin secretion from islets from Sprague-Dawley rats was measured in batch incubations. Cytoplasmic free Ca(2+) concentration was measured from single β-cells by fura-2-based microfluorometry.Triphenylphosphine oxide did not alter insulin secretion and [Ca(2+)](i) response triggered by KCl or fructose. It inhibited insulin secretion in response to glucose, L-arginine, and glucagon-like peptide 1. It also inhibited glucose-induced insulin secretion by mechanisms that are independent of the adenosine triphosphate-sensitive potassium channels and [Ca(2+)](i) increase.Our results suggest that in the rat islets, TRPM5 is involved in mediating insulin secretion by glucose and l-arginine and in potentiating the glucose-induced insulin secretion by glucagon-like peptide 1.