title: Plasma corticosterone levels is elevated in rats submitted to chronic intermittent hypoxia.
abstract: In the present study we investigated whether plasma corticosterone is altered in rats exposed to chronic intermittent hypoxia (CIH). Rats were submitted to a fraction of inspired oxygen of 6%, for 40 s, every 9 min, 8 h a day, for 35 days (CIH rats, n=17), while control rats were maintained under normoxic conditions (n=16). After CIH, the rats presented a significant increase in baseline mean arterial pressure (118+/-2 vs 106+/-3, mmHg) but not in baseline heart rate (381+/-17 vs 362+/-12 bpm) when compared to the control rats. Besides, a significant increase in plasma corticosterone was observed in CIH rats in comparison to the control rats (39+/-4 vs 20+/-2 microg/dl). Considering that corticosterone can affect both peripheral and central sympathetic mechanisms, the elevated plasma corticosterone may represent a new insight on the mechanisms underlying the hypertension observed after CIH.
authors.affiliation: Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, SP, Brazil.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Zoccal
authors.forename: Leni G H
authors.initials: LG
authors.lastname: Bonagamba
authors.forename: José
authors.initials: J
authors.lastname: Antunes-Rodrigues
authors.forename: Benedito H
authors.initials: BH
authors.lastname: Machado
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D002908:Chronic Disease; D003345:Corticosterone / Q000097:blood*; D006339:Heart Rate / Q000502:physiology; D006973:Hypertension / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D000860:Hypoxia / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D008297:Male; D010100:Oxygen / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013564:Sympathetic Nervous System / Q000502:physiology*
chemical_list: D010100:Oxygen; D003345:Corticosterone