Acute food deprivation and chronic food restriction differentially affect hypothalamic NPY mRNA expression.
Although acute food deprivation and chronic food restriction both result in body weight loss, they produce different metabolic states. To evaluate how these two treatments affect hypothalamic peptide systems involved in energy homeostasis, we compared patterns of hypothalamic neuropeptide Y (NPY), agouti-related protein (AgRP), proopiomelanocotin (POMC), and leptin receptor gene expression in acutely food-deprived and chronically food-restricted rats. Both acute food deprivation and chronic food restriction reduced body weight and circulating leptin levels and resulted in increased arcuate NPY and decreased arcuate POMC gene expression. Arcuate AgRP mRNA levels were only elevated in acutely deprived rats. NPY gene expression was increased in the compact subregion of the dorsomedial hypothalamus (DMH) in response to chronic food restriction, but not in response to acute food deprivation. Leptin receptor expression was not affected by either treatment. Double in situ hybridization histochemistry revealed that, in contrast to the situation in the arcuate nucleus, NPY and leptin receptor mRNA-expressing neurons were not colocalized in the DMH. Together, these data suggest that arcuate and DMH NPY gene expression are differentially regulated. DMH NPY-expressing neurons do not appear to be under the direct control of leptin signaling.
Bi
Sheng
S
Dept. of Psychiatry and Behavioral Sciences, Johns Hopkins Univ. School of Medicine, 720 Rutland Ave., Ross 618, Baltimore, MD 21205, USA. sbi@jhmi.edu
Robinson
Benjamin M
BM
Moran
Timothy H
TH
D054369:Agouti-Related Protein; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000502:physiology; D004302:Dorsomedial Hypothalamic Nucleus / Q000502:physiology*; D002149:Energy Intake / Q000502:physiology*; D005508:Food Deprivation / Q000502:physiology*; D015870:Gene Expression / Q000502:physiology; D007328:Insulin / Q000097:blood; D036341:Intercellular Signaling Peptides and Proteins; D020738:Leptin / Q000097:blood; D008297:Male; D009478:Neuropeptide Y / Q000235:genetics*; D011333:Pro-Opiomelanocortin / Q000235:genetics; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000235:genetics; D054411:Receptors, Leptin
C515197:AGRP protein, rat; D054369:Agouti-Related Protein; D001786:Blood Glucose; D007328:Insulin; D036341:Intercellular Signaling Peptides and Proteins; D020738:Leptin; D009478:Neuropeptide Y; D011506:Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; D011333:Pro-Opiomelanocortin