TY - JOUR
T1 - Evidence that growth hormone exerts a feedback effect on stomach ghrelin production and secretion
AU - Qi, Xiang
AU - Reed, Jason
AU - Englander, Ella W.
AU - Chandrashekar, Varadaraj
AU - Bartke, Andrzej
AU - Greeley, George H.
PY - 2003/10
Y1 - 2003/10
N2 - Ghrelin is a recently discovered stomach hormone that stimulates pituitary growth hormone (GH) secretion potently. The purpose of these experiments was to test the hypothesis that a stomach-ghrelin-pituitary-GH axis exists in which either an elevation or reduction in systemic GH levels will exert a negative or positive feedback action, respectively, on stomach ghrelin homeostasis. In rats, GH administration decreased stomach ghrelin mRNA levels and plasma ghrelin levels significantly. In GH-releasing hormone (GHRH) transgenic mice, GHRH overexpression decreased stomach ghrelin peptide levels when compared wlth control mice. In aged rats (25 months) stomach ghrelin mRNA and peptide levels and plasma ghrelin levels were decreased when compared with young rats (5 months). Because GH secretion is reduced in aged rats, the elevated stomach ghrelin production and secretion may reflect a decreased GH feedback on stomach ghrelin, homeostasis, and secretion. Together, these findings suggest that endogenous pituitary GH exerts a feedback action on stomach ghrelin homeostasis and support the hypothesls that a stomach-ghrelin-pituitary GH axis exists.
AB - Ghrelin is a recently discovered stomach hormone that stimulates pituitary growth hormone (GH) secretion potently. The purpose of these experiments was to test the hypothesis that a stomach-ghrelin-pituitary-GH axis exists in which either an elevation or reduction in systemic GH levels will exert a negative or positive feedback action, respectively, on stomach ghrelin homeostasis. In rats, GH administration decreased stomach ghrelin mRNA levels and plasma ghrelin levels significantly. In GH-releasing hormone (GHRH) transgenic mice, GHRH overexpression decreased stomach ghrelin peptide levels when compared wlth control mice. In aged rats (25 months) stomach ghrelin mRNA and peptide levels and plasma ghrelin levels were decreased when compared with young rats (5 months). Because GH secretion is reduced in aged rats, the elevated stomach ghrelin production and secretion may reflect a decreased GH feedback on stomach ghrelin, homeostasis, and secretion. Together, these findings suggest that endogenous pituitary GH exerts a feedback action on stomach ghrelin homeostasis and support the hypothesls that a stomach-ghrelin-pituitary GH axis exists.
KW - Mouse
KW - Pituitary
KW - Rat
UR - http://www.scopus.com/inward/record.url?scp=0141752799&partnerID=8YFLogxK
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U2 - 10.1177/153537020322800907
DO - 10.1177/153537020322800907
M3 - Article
C2 - 14530511
AN - SCOPUS:0141752799
SN - 1535-3702
VL - 228
SP - 1028
EP - 1032
JO - Experimental Biology and Medicine
JF - Experimental Biology and Medicine
IS - 9
ER -