Orexigenic effects of a growth hormone secretagogue and nitric oxide in aged rats and dogs: correlation with the hypothalamic expression of some neuropeptidergic/receptorial effectors mediating food intake.
Hypothalamic neurochemical alterations in mammals underlie disturbances of food intake. There is scarce information on these topics in elderly persons; therefore, the aims of the present study were: (i) to evaluate the orexigenic effects of a growth hormone secretagogue, administered to young and old rats and dogs, alone or in combination with molsidomine, a donor of nitric oxide and (ii) to evaluate by reverse transcription-polymerase chain reaction in the whole hypothalamus of young and old rats messenger RNA levels of a wide number of anabolic and catabolic peptides, receptors, and enzymes involved in the control of feeding behavior, relating the detected titers, whenever possible, to the feeding responses to growth hormone secretagogue. In all, the results obtained strengthen the proposition that, in the hypothalamus of old rats, anti-anorexigenic compensatory mechanisms are operative, aimed at maintaining a "normal" feeding pattern. Thus, the occurrence of a primary, age-related alteration in the feeding mechanisms is unlikely.
Rigamonti
Antonello E
AE
Department of Medical Pharmacology, Center of Excellence on Neurogenerative Diseases, University of Milan, via Vanvitelli 32, 20129 Milan, Italy.
Bonomo
Sara M
SM
Scanniffio
Diego
D
Cella
Silvano G
SG
Müller
Eugenio E
EE
D000367:Age Factors; D000818:Animals; D001066:Appetite / Q000187:drug effects*; D004285:Dogs; D004435:Eating / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D054439:Ghrelin; D013006:Growth Hormone / Q000494:pharmacology*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008981:Molsidomine / Q000494:pharmacology*; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D036361:Peptide Hormones / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018013:Receptors, Neuropeptide / Q000235:genetics / Q000378:metabolism
D054439:Ghrelin; D009479:Neuropeptides; D020030:Nitric Oxide Donors; D036361:Peptide Hormones; D012333:RNA, Messenger; D018013:Receptors, Neuropeptide; D013006:Growth Hormone; D008981:Molsidomine