Central administration of α-melanocyte stimulating hormone inhibits fasting- and neuropeptide Y-induced feeding in neonatal chicks

Kawakami, S.; Bungo, Takashi; Ando, Ryuichi; Ohgushi, Atsushi; Shimojo, Masataka; Masuda, Yuichi; Furuse, Mitsuhiro

doi:10.1016/s0014-2999(00)00344-7

Cited by 81 publications

(36 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…AVT stimulates the release of α-MSH from cultured pituitary cells (Castro et al 1988), and the results of our study suggest that this effect is likely to be exerted via AVT binding to VT2R. α-MSH is known as a potent food-intake inhibitor in chickens and quail (Kawakami et al 2000;Boswell and Takeuchi 2005) and may therefore mediate AVT-induced inhibition of feeding behavior (Tachibana et al 2004). This raises the possibility that stress-induced AVT/AVP release from the median eminence into portal blood stimulates the secretion of α-MSH from the pituitary resulting in stress-associated anorexia (Vergoni and Bertolini 2000;Tachibana et al 2007).…”

Section: Vt2r In Corticotropes/melanotropesmentioning

confidence: 58%

Immunohistochemical characterization of chicken pituitary cells containing the vasotocin VT2 receptor

et al. 2008

View full text Add to dashboard Cite

Research in mammals has demonstrated a variety of regulatory effects of vasopressin and oxytocin on endocrine functions of the anterior pituitary gland. Less evidence is available regarding the hypophysiotropic action of arginine vasotocin (AVT) comprising vasopressic and oxytocic activities in birds. Some hypophysiotropic effects of AVT may result from its interactions with brain circuits controlling pituitary functions, whereas others are caused by its direct affect on pituitary cells. Use of an antiserum to the vasotocin receptor VT2 (VT2R) has revealed numerous immunoreactive cells in the anterior pituitary gland of the chicken. The objective of the present study has been to identify endocrine phenotypes of chicken pituitary cells containing VT2R by means of immunohistochemical labeling. VT2R immunoreactivity has been found in all cells immunoreactive for adrenocorticotropin and alpha-melanotropin. Approximately 10% of labeled lactotropes are also immunoreactive for VT2R and lie around the anatomical boundary dividing the cephalic and caudal lobes. In both corticotropes/melanotropes and lactotropes, immunoreactive VT2R is present in a narrow layer outlining cell bodies. Immunoreactive VT2R is not found in gonadotropes, thyrotropes, or somatotropes. These results provide evidence for the important role of VT2Rs in mediating effects of AVT on endocrine secretion from corticotropes and, partially, from lactotropes.

show abstract

Section: Vt2r In Corticotropes/melanotropesmentioning

confidence: 58%

Immunohistochemical characterization of chicken pituitary cells containing the vasotocin VT2 receptor

et al. 2008

View full text Add to dashboard Cite

show abstract

“…The finding in the present study and in the chicken (Gerets et al 2000) of the co-localization of POMC mRNA and a-MSH peptide in individual IN neuronal cell bodies demonstrates the capability of these cells to synthesize a-MSH. This can be related to the observation that central administration of a-MSH decreases food intake in domestic chicks (Kawakami et al 2000).…”

Section: Discussionmentioning

confidence: 89%

“…Although a functional role for the melanocortin system in regulating food intake in birds remains to be fully established, mammalian AGRP and a-MSH peptides administered into the brain of the domestic chick and the ring dove (Streptopelia risoria) exert comparable effects on feeding to those seen in mammals. Thus, a-MSH inhibits the stimulatory effects on food intake of fasting and NPY administration, whereas AGRP conversely increases feeding and attenuates the inhibitory effect of a-MSH (Kawakami et al 2000;Tachibana et al 2001;Strader et al 2003). Furthermore, a recent study in the ring dove has demonstrated that the selective MC4-R antagonist HS014 and the MC3-R and MC4-R agonist MTII, respectively, increase and decrease food intake when administered into the brain (Strader et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Fasting differentially regulates expression of agouti-related peptide, pro-opiomelanocortin, prepro-orexin, and vasoactive intestinal polypeptide mRNAs in the hypothalamus of Japanese quail

Phillips-Singh

Tanaka

et al. 2003

Cell and Tissue Research

View full text Add to dashboard Cite

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 prepro-orexin in the lateral hypothalamic area (LHy) and periventricular hypothalamic nucleus, and for VIP in the LHy. POMC mRNA was co-localized with alpha-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.

show abstract

“…There is also a similarity between the expression profiles of chicken POMC and MCR genes and those of their mammalian homologs, although in chicken there is more pronounced expression in the peripheral tissues (Ottaviani et al 1997, Gerets et al 2000, Ling et al 2004. Intracerebroventricular injection of MC3/4R agonists in neonatal chicks or ringdoves has been shown to significantly inhibit food intake (Kawakami et al 2000, Tachibana et al 2001, Strader et al 2003, as well as neuropeptide Y-induced feeding when neuropeptide Y is given simultaneously (Kawakami et al 2000). However, this is the first report describing the effect of peripherally administered MC3/4R agonist on chickens, a comparison between the two commercial chicken strains representing obese and lean phenotypes, and a comparative analysis of POMC gene expression in the hypothalamus.…”

Section: Introductionmentioning

confidence: 94%

The melanocortin circuit in obese and lean strains of chicks

Hen

Yosefi

Simchaev

et al. 2006

Journal of Endocrinology

View full text Add to dashboard Cite

Agonists of membranal melanocortin 3 and 4 receptors (MC3/4Rs) are known to take part in the complex control mechanism of energy balance. In this study, we compared the physiological response to an exogenous MC3/4R agonist and the hypothalamic expression of proopic melanocortin (POMC) gene, encoding few MC3/4R ligands, between broiler and layer chicken strains. These strains, representing the two most prominent commercial strains of chickens grown for meat (broilers) and egg production (layers), differ in their food intake, fat accumulation, and reproductive performance and, therefore, form a good model of obese and lean phenotypes, respectively. A single i.v. injection of the synthetic peptide melanotan-II (MT-II; 1 mg/kg body weight) into the wing vein of feed-restricted birds led to attenuation of food intake upon exposure to feeding ad libitum in both broiler and layer chickens. A study of the POMC mRNA encoding the two prominent natural MC3/4R agonists, a-MSH and ACTH, also revealed a general similarity between the strains. Under feeding conditions ad libitum, POMC mRNA levels were highly similar in chicks of both strains and this level was significantly reduced upon feed restriction. However, POMC mRNA down-regulation upon feed restriction was more pronounced in layers than in broilers. These results suggest: (i) a role for MC3/4R agonists in the control of appetite; (ii) that the physiological differences between broilers and layers are not related to unresponsiveness of broiler chickens to the satiety signal of MC3/4R ligands. Therefore, these findings suggest that artificial activation of this circuit in broiler chicks could help to accommodate with their agricultural shortcomings of overeating, fattening, and impaired reproduction.

show abstract

Central administration of α-melanocyte stimulating hormone inhibits fasting- and neuropeptide Y-induced feeding in neonatal chicks

Cited by 81 publications

References 21 publications

Immunohistochemical characterization of chicken pituitary cells containing the vasotocin VT2 receptor

Immunohistochemical characterization of chicken pituitary cells containing the vasotocin VT2 receptor

Fasting differentially regulates expression of agouti-related peptide, pro-opiomelanocortin, prepro-orexin, and vasoactive intestinal polypeptide mRNAs in the hypothalamus of Japanese quail

The melanocortin circuit in obese and lean strains of chicks

Contact Info

Product

Resources

About