Plasma corticosterone levels is elevated in rats submitted to chronic intermittent hypoxia.
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.
Zoccal
Daniel B
DB
Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, SP, Brazil.
Bonagamba
Leni G H
LG
Antunes-Rodrigues
José
J
Machado
Benedito H
BH
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*
D010100:Oxygen; D003345:Corticosterone