Short-term cold exposure may cause a local decrease of neuropeptide Y in the rat hypothalamus.
Neuropeptide Y (NPY) is an orexigenic and hypothermic peptide. To understand its role in hypothermic conditions, male rats were placed in a 24 degrees C or 4 degrees C air chamber for 1.5 h. The expression of c-Fos protein, and NPY mRNA and protein, was analyzed in the hypothalamus 1 h-2 h later. The cold treatment increased the number of c-Fos-immunoreactive cells in the paraventricular hypothalamic nucleus (PVN) and arcuate nucleus (ARC). At the same time it decreased the density of NPY-immunoreactive components in the PVN, dorsomedial hypothalamic nucleus and ARC, as well as of NPY transcripts in the PVN and ARC. No colocalization of c-Fos with NPY was detected. These results suggest that short-term cold exposure should reduce indirectly NPY production in some hypothalamic nuclei to facilitate thermogenesis without inducing feeding behavior.
Park
Joong Jean
JJ
Department of Physiology, College of Medicine, Korea University, Seoul 136-705, Korea. parkjj@korea.ac.kr
Lee
Heung Kyung
HK
Shin
Min Woo
MW
Kim
Sung Jin
SJ
Noh
Seung Yeon
SY
Shin
Jin
J
Yu
Woo Sung
WS
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology; D001833:Body Temperature Regulation; D004302:Dorsomedial Hypothalamic Nucleus / Q000166:cytology; D005786:Gene Expression Regulation; D006339:Heart Rate; D007031:Hypothalamus / Q000378:metabolism*; D007036:Hypothermia, Induced; D008297:Male; D009043:Motor Activity; D009478:Neuropeptide Y / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D009478:Neuropeptide Y; D016760:Proto-Oncogene Proteins c-fos