The Effects of Prolactin on Aspects of Carbohydrate, Lipid and Amino Acid Metabolism in the Goldfish Carassius Auratus

Unlike other pituitary hormones, prolactin affects a broad spectrum of physiological systems. Of the over 100 reported actions of prolactin, a majority are related to the involvement of this hormone in reproduction, growth and development. In teleost fishes, as in other non-mammalian species, seasonal reproductive cycles involve dramatic changes in carbohydrate and lipid metabolism. The hormonal control of these seasonal, reproductively related, metabolic shifts remains to be elucidated. As prolactin has been implicated in the control of carbohydrate and lipid metabolism throughout most classes in the vertebrate group, this study examines the effects of prolactin on specific aspects of carbohydrate and lipid metabolism in fish. In view of the fact that prolactin and growth hormone are structurally similar, and since overlap in activities are commonly noted, the action of these hormones on carbohydrate, lipid and amino acid metabolism were compared. Since prolactin has been reported to have growth-promoting effects in all vertebrates except the fishes, the examination of the effects of prolactin on growth and amino acid metabolism is of particular interest