Neuronal NO Synthase and Its Inhibitor PIN Are Present and Influenced by Glucose in the Human β-Cell Line CM and in Rat INS-1 Cells

Abstract

Nitric oxide (NO) is synthesised by different nitric oxide synthases (NOS) from L-arginine and acts as a signal transducer in a variety of cells. The neuronal isoenzyme of NOS (nNOS) was recently found in rodent beta-cells and beta-cell lines. We provide evidence that nNOS is also present in the human beta-cell line CM and that the specific inhibitor of nNOS PIN is expressed in CM and INS-1 cells. Furthermore, we investigated the influence of glucose on the activity of nNOS and the expression of PIN and are able to show that both are increased by glucose stimulation in the beta-cell lines but not in the mouse fibroblastic cell line LTK. This indicates that nNOS and PIN play a role in the specific function of beta-cells, not only in rodents but also in humans.

Similarity in Transcytosis of nNOSα in Enteric Nerve Terminals and Beta Cells of Pancreatic Islet

“…Reliable evidence exists that in the beta cells of the pancreas, nNOS alpha isoform exists ( 17 , 18 ). This is seen in rat, mice, and human islets ( 32 ). nNOS alpha dimer binds to the core of insulin granules and also concentrated in the subterminal membranes ( 17 ).…”