Acute and chronic cardiovascular effects of intermittent hypoxia in C57BL/6J mice.
We investigated the effects of 1) acute hypoxia and 2) 5 wk of chronic intermittent hypoxia (IH) on the systemic and pulmonary circulations of C57BL/6J mice. Mice were chronically instrumented with either femoral artery or right ventricular catheters. In response to acute hypoxia (4 min of 10% O2; n = 6), systemic arterial blood pressure fell (P < 0.005) from 107.7 +/- 2.5 to 84.7 +/- 6.5 mmHg, whereas right ventricular pressure increased (P < 0.005) from 11.7 +/- 0.8 to 14.9 +/- 1.3 mmHg. Another cohort of mice was then exposed to IH for 5 wk (O2 nadir = 5%, 60-s cycles, 12 h/day) and then implanted with catheters. In response to 5 wk of chronic IH, mice (n = 8) increased systemic blood pressure by 7.5 mmHg, left ventricle + septum weight by 32.2 +/- 7.5 x 10(-2) g/100 g body wt (P < 0.015), and right ventricle weight by 19.3 +/- 3.2 x 10(-2) g/100 g body wt (P < 0.001), resulting in a 14% increase in the right ventricle/left ventricle + septum weight (P < 0.005). We conclude that in C57BL/6J mice 1) acute hypoxia causes opposite effects on the pulmonary and systemic circulations, leading to preferential loading of the right heart; and 2) chronic IH in mice results in mild to moderate systemic and pulmonary hypertension, with resultant left- and right-sided ventricular hypertrophy.
Division of Toxicology, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, USA.
M J
MJ
Campen
L A
LA
Shimoda
C P
CP
O'Donnell
D000208:Acute Disease; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D002245:Carbon Dioxide / Q000097:blood; D002908:Chronic Disease; D003243:Consciousness; D006339:Heart Rate / Q000502:physiology; D006976:Hypertension, Pulmonary / Q000503:physiopathology; D017379:Hypertrophy, Left Ventricular / Q000503:physiopathology*; D017380:Hypertrophy, Right Ventricular / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010100:Oxygen / Q000097:blood; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D016278:Ventricular Function, Right / Q000502:physiology
D002245:Carbon Dioxide; D010100:Oxygen