TY - JOUR
T1 - Ghrelin differentially modulates the GH secretory response to GHRH between the fed and fasted states in sheep
AU - Takahashi, H.
AU - Kurose, Y.
AU - Suzuki, Y.
AU - Kojima, M.
AU - Yamaguchi, T.
AU - Yoshida, Y.
AU - Ogino, M.
AU - Hodate, K.
AU - Azuma, Y.
AU - Sugino, T.
AU - Kojima, M.
AU - Kangawa, K.
AU - Hasegawa, Y.
AU - Kobayashi, S.
N1 - Funding Information:
The authors are grateful to Professor Tsutomu Hashizume (Faculty of Agriculture, Iwate University) for his kind advice on experimental procedures. We thank Dr. A.F. Parlow and the NIDDK's National Hormone and Pituitary Program for the ovine GH and GH antibody. We are grateful to Muneyuki Sakaida, Syunichiro Sato, and Yusuke Suzuki for their excellent help in conducting this study. This study was partially supported by funding from the High Technology Research Center Development Program of the Ministry of Education, Culture, Sports, Science, and Technology, Japan.
PY - 2009/7
Y1 - 2009/7
N2 - The effect of energy balance on the growth hormone (GH) secretory responsiveness to growth hormone-releasing hormone (GHRH) has not been determined in ruminant animals. Therefore, we examined the effects of intravenous injections of 0, 3.3, and 6.6 μg ghrelin/kg body weight (BW), with and without GHRH at 0.25 μg/kg BW, on GH secretory responsiveness in both the fed and fasted sheep. The injections were carried out at 48 h (Fasting state) and 3 h (Satiety state) after feeding. Blood samples were taken every 10 minutes, from 30 minutes before to 120 minutes after the injection. Low (3.3 μg/kg BW) and high (6.6 μg/kg BW) doses of ghrelin stimulated GH secretion significantly (P < .05) greater in the Satiety state than in the Fasting state. Growth hormone-releasing hormone plus both doses of ghrelin stimulated GH secretion significantly (P < .05) greater in the Satiety state than in the Fasting state. Ghrelin and GHRH exerted a synergistic effect in the Satiety state, but not in the Fasting state. Plasma ghrelin levels were maintained significantly (P < .05) greater in the Fasting state than in the Satiety state except the temporal increases after ghrelin administration. Plasma free fatty acid (FFA) concentrations were significantly (P < .01) greater in the Fasting state than in the Satiety state. In conclusion, the present study has demonstrated for the first time that ghrelin differentially modulates GH secretory response to GHRH according to feeding states in ruminant animals.
AB - The effect of energy balance on the growth hormone (GH) secretory responsiveness to growth hormone-releasing hormone (GHRH) has not been determined in ruminant animals. Therefore, we examined the effects of intravenous injections of 0, 3.3, and 6.6 μg ghrelin/kg body weight (BW), with and without GHRH at 0.25 μg/kg BW, on GH secretory responsiveness in both the fed and fasted sheep. The injections were carried out at 48 h (Fasting state) and 3 h (Satiety state) after feeding. Blood samples were taken every 10 minutes, from 30 minutes before to 120 minutes after the injection. Low (3.3 μg/kg BW) and high (6.6 μg/kg BW) doses of ghrelin stimulated GH secretion significantly (P < .05) greater in the Satiety state than in the Fasting state. Growth hormone-releasing hormone plus both doses of ghrelin stimulated GH secretion significantly (P < .05) greater in the Satiety state than in the Fasting state. Ghrelin and GHRH exerted a synergistic effect in the Satiety state, but not in the Fasting state. Plasma ghrelin levels were maintained significantly (P < .05) greater in the Fasting state than in the Satiety state except the temporal increases after ghrelin administration. Plasma free fatty acid (FFA) concentrations were significantly (P < .01) greater in the Fasting state than in the Satiety state. In conclusion, the present study has demonstrated for the first time that ghrelin differentially modulates GH secretory response to GHRH according to feeding states in ruminant animals.
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U2 - 10.1016/j.domaniend.2009.02.003
DO - 10.1016/j.domaniend.2009.02.003
M3 - Article
C2 - 19342191
AN - SCOPUS:67349144169
SN - 0739-7240
VL - 37
SP - 55
EP - 60
JO - Domestic Animal Endocrinology
JF - Domestic Animal Endocrinology
IS - 1
ER -