SHERIDAN, Mark A.; KITTILSON, Jeffrey D.; North Dakota State University; North Dakota State University: The Role of Somatostatins in the Regulation of Metabolism

Somatostatins (SSs) are a structurally and functional diverse family of peptide hormones. Among the vast array of biological functions coordinated by the SSs are secretotropic effects as well as a host of developmental and metabolic effects. Somatostatins have been shown to promote both lipid and carbohydrate breakdown in fish and in lamprey. Lipolytic effects proceed from the breakdown of stored triacylglycerol (TG) via the stimulation of TG lipase and result in elevation of fatty acids in the plasma. In a similar fashion, SSs promote glycogen breakdown via glycogen phosphorylase and result in elevation of glucose in plasma. Such direct actions on intermediary metabolism are supported by indirect effects mediated by secretotropic actions of SS. For example, SSs inhibit the release of insulin, the absence of which favors lipolysis and glycogenolysis over lipogenesis and glycogenesis. SSs also interact with the thyroid and reproductive axes of fish, findings suggesting that SSs serve to modulate energy partitioning among growth, development, and reproductive processes. This work was supported by NSF grant IBN 0076416 to M.A.S.