title: Down-regulation of corticotropin-releasing hormone receptor type 2beta mRNA expression in the rat cardiovascular system following food deprivation.
abstract: The present study was conducted to assess the effect of nutritional stress induced by food deprivation on expression of messenger ribonucleic acid (mRNA) for corticotropin-releasing hormone receptor type 2beta (CRH-R2beta) in the rat cardiovascular system in the presence or absence of changes in circulating corticosterone. Food deprivation for 96 h caused a robust increase in plasma corticosterone levels and a significant decrease in CRH-R2beta mRNA expression in the rat heart. Starvation for 48 and 96 h decreased CRH-R2beta mRNA expression in the atria, ventricle as well as aorta of sham-adrenalectomized (sham) rats. Surprisingly, clamping plasma glucocorticoids at low levels by adrenalectomy with corticosterone pellet replacement (ADX+B) did not completely prevent starvation-induced decreases of CRH-R2beta mRNA expression in the rat cardiovascular system. Urocortin (Ucn) mRNA expression was increased significantly by food deprivation in the heart of sham as well as ADX+B rats. We speculate that food deprivation may increase urocortin, which in turn down-regulates CRH-R2beta mRNA expression in cardiovascular system. These data indicate that food deprivation despite the presence or absence of changes in circulating corticosterone may have an inhibitory effect on CRH-R2beta mRNA expression in the rat cardiovascular system.
authors.affiliation: Second Department of Internal Medicine, Kochi Medical School, Kohasu, Okoh-cho, Nankoku 783-8505, Japan. pour@med.kochi-ms.ac.jp
authors.forename: Hossein Pournajafi
authors.initials: HP
authors.lastname: Nazarloo
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Nishiyama
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Koichi
authors.initials: K
authors.lastname: Asaba
authors.forename: Kozo
authors.initials: K
authors.lastname: Hashimoto
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism; D000315:Adrenalectomy; D000818:Animals; D001835:Body Weight; D002319:Cardiovascular System / Q000378:metabolism; D003345:Corticosterone / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000235:genetics; D015536:Down-Regulation; D005215:Fasting / Q000378:metabolism*; D005508:Food Deprivation; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D009929:Organ Size; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018019:Receptors, Corticotropin-Releasing Hormone / Q000235:genetics*; D013950:Thymus Gland; D054832:Urocortins
chemical_list: D012333:RNA, Messenger; D018019:Receptors, Corticotropin-Releasing Hormone; D054832:Urocortins; D003346:Corticotropin-Releasing Hormone; D003345:Corticosterone