Influence of nutritional deprivation on insulin-like growth factor I, somatotropin, and metabolic hormones in swine.

摘要: Although growth hormone (GH) is a primary stimulus for the synthesis of insulin-like factor I (IGF-I), other factors such as nutritional status, insulin, and thyroid hormones are important modulators circulating IGF-I levels. Thus, effects feed restriction subsequent refeeding on plasma levels IGF-I, GH, were studied in swine. Despite an elevation GH after 48 h restriction, decreased by 53% (P less than .05). Plasma triiodothyronine (T3) insulin lower .05) within 24 began, whereas thyroxine (T4) did not decrease until removal feed. Blood glucose remained unchanged throughout experiment. Refeeding 48-h fast was associated with decline 2 h, concomitant T3. fasted pigs increase IGF-I; however, still had returned to prefast concentrations refeeding. These data indicate that GH-IGF-I axis becomes uncoupled during swine inadequate nutrient supply may limit expression anabolic GH.