Abstrato

Role of Pancreatic Thyrotropin releasing Hormone in Directing Insulin Secretion to Regulatory Pathway

Dr. Vladimir Strbak

 Thyrotropin releasing hormone (TRH; pGlu-His-ProNH2) is expressed also in pancreatic β cells where it is colocalized in secretory granules with insulin. High perinatal changes of the TRH gene expression and TRH concentrations in rat pancreatic islets coincide with the perinatal maturation of the adequate insulin secretory responsiveness to glucose and other nutrient secretagogues. TRH secretion from pancreatic islets is stimulated by glucose and inhibited by insulin. Disruption of the TRH gene in knockout mice results in hyperglycaemia accompanied by impaired insulin secretory response to glucose. Progress in understanding TRH - insulin relations may be substantial for improving knowledge of pathophysiological mechanisms included in changes of insulin secretion with possible clinical impact. Block of the last step of biosynthesis of α-amidated peptides, including TRH by disulfiram (DS) treatment of adult male rats subcutaneously with 200 mg/kg for five days in our experiments resulted in barely detectable levels of peptidyl-glycine α-amidating monooxygenase (PAM) in their pancreatic islets. TRH in physiological concentration