Signal transduction in osmotically induced hormone secretion

Abstract

Cell swelling caused by extracellular hyposmolarity or isosmolar permeant molecules (e.g., ethanol, urea, etc.) evokes immediate secretion of peptides and proteohormones stored in secretory vesicles. It was the aim of our work to analyze signalling in the transduction pathway resulting in exocytosis of thyrotropin-releasing hormone (pGlu-His-Pro-NH2), TRH.Isolated rat pancreatic islets or hypothalamic structures were exposed to different media in four successive 30-min-long incubations.Inhibition ofpeptidyl-glycine ~ amidating monooxygenase (the enzyme controlling the final step of TRH maturation) by 8 ~tM disulfiram decreased basal secretion of TRH by pancreatic islets to barely detectable levels and prevented its release after stimulation. Ethanol