Expressions of the prepro-orexin and orexin type 2 receptor genes in obese rat.
We examined the expressions of the prepro-orexin gene in the lateral hypothalamic area (LHA), the genes of the neuropeptide Y (NPY) and proopiomelanocortin (POMC) in the arcuate nucleus (ARC), the orexin type 1 receptor (OX1R) gene in the ventromedial hypothalamic nucleus (VMH) and the orexin type 2 receptor (OX2R) gene in the paraventricular nucleus (PVN) in 6-, 12- and 18-week-old male lean (Fa/?) and obese (fa/fa) Zucker rats, using in situ hybridization histochemistry. The fa/fa rats showed hyperglycemia at 12- and 18-week-old. The prepro-orexin mRNA level in fa/fa rats at 18-week-old and the OX2R mRNA level in fa/fa rats at 12- and 18-week-old were significantly decreased compared to controls. The NPY mRNA levels in fa/fa rats at each time point were significantly increased compared to controls, but the POMC mRNA levels were decreased. Prepro-orexin and OX2R mRNA levels in fa/fa rats pretreated with insulin normalized to the levels found in Fa/? rats. These results suggest that the regulation of prepro-orexin gene expression might be independent of the regulation of the NPY and POMC genes in the ARC in fa/fa rats.
Yamamoto
Yukiyo
Y
Department of Physiology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, Japan.
Ueta
Yoichi
Y
Yamashita
Hiroshi
H
Asayama
Kohtaro
K
Shirahata
Akira
A
D000818:Animals; D001835:Body Weight; D002352:Carrier Proteins / Q000378:metabolism; D006943:Hyperglycemia / Q000378:metabolism; D017403:In Situ Hybridization; D007328:Insulin / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D009479:Neuropeptides / Q000096:biosynthesis* / Q000378:metabolism; D064446:Orexin Receptors; D000068797:Orexins; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism; D011498:Protein Precursors / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011924:Rats, Zucker; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide / Q000096:biosynthesis*; D013997:Time Factors; D014697:Ventromedial Hypothalamic Nucleus / Q000378:metabolism
D002352:Carrier Proteins; C578627:Hcrtr1 protein, rat; D007328:Insulin; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D064446:Orexin Receptors; D000068797:Orexins; D011498:Protein Precursors; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide