Plasma Levels of Growth Hormone and Insulin in Protein Malnourished vs Normal Growing Pigs in Response to Arginine or Glucose Infusion

Publisher Website
Google Scholar
Abstract
Sixteen male Yorkshire growing pigs fitted with indwelling jugular catheters were used to measure effects of arginine (.5 g/kg.75 body weight) infusion over a 30-min period or glucose (1 g/kg.75 body weight) infusion over a 3-min period on plasma growth hormone (GH), insulin, glucose and free fatty acid (FFA) concentrations. Arginine or glucose infusions were given following an overnight fast and blood samples were obtained at 15-min intervals for 2 hr after the beginning of arginine or glucose infusion. An additional sample was taken 4 hr after the beginning of arginine infusion. There were four pigs in each of four dietary groups as follows: Group 1 — control (C) pigs fed an adequate diet throughout postnatal life to 12 weeks of age, and from dams fed an adequate diet during gestation; Group 2 — pigs (deficient during gestation, DG) fed an adequate diet throughout postnatal life to 12 weeks of age, but from dams fed a diet containing .5% protein during gestation; Group 3 — pigs (deficient after weaning, DW) fed a low (6%) protein diet from 4 to 12 weeks of age, and from dams fed an adequate gestation diet; Group 4 — pigs (deficient after weaning, then rehabilitated, DWR) fed a low (6%) protein diet from 4 to 12 weeks of age (as group 3), then fed an adequate diet for 8 weeks to 20 weeks of age. Basal plasma GH concentration was higher and plasma insulin concentration was lower in C pigs than in pigs in any of the other three groups. Arginine infusion produced a delayed rise in plasma GH level in DG and DWR pigs compared to C pigs. There was no response of plasma GH to arginine infusion in DW pigs. Plasma insulin of C pigs was significantly (P<.05) increased 45 min after arginine infusion, but there was no response in protein malnourished pigs (DG, DW and DWR). Arginine infusion caused a significant rise (P<.05) in plasma glucose in C pigs at 60 and 90 min, but no change in the other three groups. Plasma FFA was significantly depressed in C pigs 30, 60 and 90 min after arginine infusion. Basal FFA levels were significantly (P<.05) higher in all three protein malnourished pigs than in C pigs and showed no change following arginine infusion. Glucose infusion resulted in a rise in plasma insulin and a drop in plasma GH in C pigs, but no change in either plasma insulin or GH level in protein malnourished pigs (DG, DW and DWR). Copyright © 1978. American Society of Animal Science . Copyright 1978 by American Society of Animal Science.