Exogenous growth hormone stimulates somatotrophic axis function and
growth in neonatal pigs.
Wester, Timothy J., Teresa A. Davis, Marta L. Fiorotto, and Douglas G.
Burrin.
USDA/ARS Children's Nutrition Research Center
APStracts 4:0208E, 1997.
We studied the effects of exogenous porcine growth hormone (pGH)
administration on circulating insulin-like growth factor I (IGF-I)
concentration, IGF-binding proteins (IGFBP) tissue growth and protein
synthesis in neonatal pigs. One-day-old pigs were given daily
intramuscular injections of either pGH [1 mg/kg body weight (BW)]
(n=6) or saline (n=5) for 7 days, after which time we measured in
vivo protein synthesis using a bolus of 3H-phenylalanine. Mean plasma
pGH concentration in pGH-treated pigs measured on day 7 was 22-fold
higher than in controls. The plasma IGF-I concentration in pGH
-treated pigs was significantly greater than controls after 1 day of
treatment and plateaued at 285% of control values after 4 days. After
7 days of treatment, plasma IGFBP-3 concentrations and the plasma
glucose response to a meal were also greater in pGH-treated than
control pigs. Porcine GH treatment significantly increased BW gain
and food conversion efficiency, and the protein synthesis rate in
several visceral organs. Our results demonstrate that exogenous pGH
increases circulating IGF-I and IGFBP-3 concentrations and visceral
organ growth in neonatal pigs, suggesting that the somatotrophic axis
is functional in the neonate.
Received 22 May 1997; accepted in final form 12 September 1997.
APS Manuscript Number E230-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 7 October 1997