TY - JOUR
T1 - Fasting differentially regulates expression of agouti-related peptide, pro-opiomelanocortin, prepro-orexin, and vasoactive intestinal polypeptide mRNAs in the hypothalamus of Japanese quail
AU - Phillips-Singh, D.
AU - Li, Q.
AU - Takeuchi, S.
AU - Ohkubo, T.
AU - Sharp, P. J.
AU - Boswell, T.
PY - 2003/8/1
Y1 - 2003/8/1
N2 - Research in mammals has established the existence of a neuronal network that lies within the hypothalamus and that regulates energy homeostasis. However, it is unknown whether this system has been evolutionarily conserved. The objective of the present study was therefore to examine the influence of the agouti-related peptide (AGRP), pro-opiomelanocortin (POMC), prepro-orexin, and vasoactive intestinal polypeptide (VIP) genes on energy balance in birds by quantifying the effect of a 24-h fast on their expression in the hypothalamus of the Japanese quail. In situ hybridization revealed strong signals for AGRP and POMC mRNAs in the infundibular nucleus (IN), for preproorexin in the lateral hypothalamic area (LHy) and periventricular hypothalamic nucleus, and for VIP in the LHy. POMC mRNA was co-localized with α -melanocyte-stimulating hormone-like immunoreactivity in individual IN neurons. Compared with the ad-libitum-fed state, a 24-h fast resulted in a 2.2-fold increased expression of AGRP mRNA in the IN. However, fasting did not induce changes in POMC, prepro-orexin, or VIP mRNAs. The results suggest an involvement of the central melanocortin system in the regulation of energy balance in birds, as in mammals. In contrast, orexins in birds may be primarily involved in the control of physiological functions other than energy homeostasis.
AB - Research in mammals has established the existence of a neuronal network that lies within the hypothalamus and that regulates energy homeostasis. However, it is unknown whether this system has been evolutionarily conserved. The objective of the present study was therefore to examine the influence of the agouti-related peptide (AGRP), pro-opiomelanocortin (POMC), prepro-orexin, and vasoactive intestinal polypeptide (VIP) genes on energy balance in birds by quantifying the effect of a 24-h fast on their expression in the hypothalamus of the Japanese quail. In situ hybridization revealed strong signals for AGRP and POMC mRNAs in the infundibular nucleus (IN), for preproorexin in the lateral hypothalamic area (LHy) and periventricular hypothalamic nucleus, and for VIP in the LHy. POMC mRNA was co-localized with α -melanocyte-stimulating hormone-like immunoreactivity in individual IN neurons. Compared with the ad-libitum-fed state, a 24-h fast resulted in a 2.2-fold increased expression of AGRP mRNA in the IN. However, fasting did not induce changes in POMC, prepro-orexin, or VIP mRNAs. The results suggest an involvement of the central melanocortin system in the regulation of energy balance in birds, as in mammals. In contrast, orexins in birds may be primarily involved in the control of physiological functions other than energy homeostasis.
KW - Brain
KW - Food intake
KW - Gene expression
KW - In situ hybridization
KW - Japanese quail (Coturnix coturnix japonica)
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U2 - 10.1007/s00441-003-0755-8
DO - 10.1007/s00441-003-0755-8
M3 - Article
C2 - 12845520
AN - SCOPUS:0037851174
SN - 0302-766X
VL - 313
SP - 217
EP - 225
JO - Cell and Tissue Research
JF - Cell and Tissue Research
IS - 2
ER -