AJP - Endocrinology and Metabolism, Vol 257, Issue 4 E554-E560, Copyright © 1989 by American Physiological Society
Insulin, growth hormone, glucose, and fatty acids in gilts selected for rapid vs. slow growth rate
S. A. Norton, M. T. Zavy, C. V. Maxwell, D. S. Buchanan and J. E. Breazile
Department of Animal Science, Oklahoma State University, Stillwater 74078.
Twelve-hour plasma profiles of growth hormone (GH), insulin, glucose, and
nonesterified free fatty acids (NEFA), as well as GH, insulin, and glucose
responses to saline, glucose, arginine, and human pancreatic growth
hormone-releasing factor (GRF) infusion were examined in 15 crossbred
gilts, selected for rapid vs. slow growth. For experiment 1 GH and insulin
patterns differed (P less than 0.05) between the rapid growth line (RGL)
and slow growth line (SGL). Mean GH concentrations in SGL and RGL gilts
were 4.1 and 3.2 ng/ml, respectively (P less than 0.05). Plasma GH profile
area was greater (P less than 0.08) for SGL than RGL gilts. Glucose level,
glucose area, and insulin level were higher (P less than 0.05) for RGL than
SGL gilts. Plasma NEFA levels and area were greater (P less than 0.05) for
SGL gilts. In experiment 2 responses of GH, insulin, and glucose to saline,
glucose, arginine, and GRF infusions varied (P less than 0.05) between and
within lines relative to control values. These results indicate that
selection for growth rate results in concomitant changes in endocrine and
metabolic status.
