TY - JOUR
T1 - Effects of ruminal infusion of volatile fatty acids on plasma concentration of growth hormone and insulin in sheep
AU - Matsunaga, N.
AU - Arakawa, N. T.
AU - Goka, T.
AU - Nam, K. T.
AU - Ohneda, A.
AU - Sasaki, Y.
AU - Katoh, Kazuo
PY - 1999/7/1
Y1 - 1999/7/1
N2 - In an initial experiment we observed postprandial changes in plasma concentrations of growth hormone (GH), insulin, glucagon, and somatostatin (SRIF) in sheep. We then examined whether increasing the rumen concentration of volatile fatty acids (VFA) by infusing a VFA mixture at three rates (53.5, 107, and 214 μmol/kg/min for 4 hr) mimicked the postprandial changes in hormone secretion. Feeding significantly (P < 0.05) suppressed the plasma GH concentration for 6 hr, whereas it significantly (P < 0.05) increased plasma concentrations of insulin, glucagon, and SRIF. Plasma glucose levels tended to decrease after feeding but then gradually increased over the prefeeding level (P < 0.05). Intraruminal infusion of the VFA mixture at 107 μmol/kg/min caused similar changes in ruminal VFA concentrations to those seen after feeding. The infusion significantly (P < 0.05) suppressed GH secretion in a dose-dependent manner, whereas it caused a significant (P < 0.05) increase in insulin and glucose concentrations without changing glucagon concentrations. From these results, we conclude that the postprandial change in ruminal VFA concentration may be a physiological signal which modifies GH and insulin secretion in sheep.
AB - In an initial experiment we observed postprandial changes in plasma concentrations of growth hormone (GH), insulin, glucagon, and somatostatin (SRIF) in sheep. We then examined whether increasing the rumen concentration of volatile fatty acids (VFA) by infusing a VFA mixture at three rates (53.5, 107, and 214 μmol/kg/min for 4 hr) mimicked the postprandial changes in hormone secretion. Feeding significantly (P < 0.05) suppressed the plasma GH concentration for 6 hr, whereas it significantly (P < 0.05) increased plasma concentrations of insulin, glucagon, and SRIF. Plasma glucose levels tended to decrease after feeding but then gradually increased over the prefeeding level (P < 0.05). Intraruminal infusion of the VFA mixture at 107 μmol/kg/min caused similar changes in ruminal VFA concentrations to those seen after feeding. The infusion significantly (P < 0.05) suppressed GH secretion in a dose-dependent manner, whereas it caused a significant (P < 0.05) increase in insulin and glucose concentrations without changing glucagon concentrations. From these results, we conclude that the postprandial change in ruminal VFA concentration may be a physiological signal which modifies GH and insulin secretion in sheep.
KW - Feeding
KW - Gh
KW - Insulin
KW - Sheep
KW - Volatile fatty acids
UR - http://www.scopus.com/inward/record.url?scp=0033167408&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033167408&partnerID=8YFLogxK
U2 - 10.1016/S0739-7240(99)00021-1
DO - 10.1016/S0739-7240(99)00021-1
M3 - Article
C2 - 10484127
AN - SCOPUS:0033167408
VL - 17
SP - 17
EP - 27
JO - Domestic Animal Endocrinology
JF - Domestic Animal Endocrinology
SN - 0739-7240
IS - 1
ER -