A sex difference in the hemodynamic effects of chronic normobaric hypoxia in rats

The packed cell volume was higher and the increase in systolic pressure in the right ventricle, as an indication of systolic pressure in the pulmonary artery, was smaller in female rats previously exposed for 4 weeks to normobaric hypercapnic hypoxia, as compared to males treated in the same way. Gonadectomy performed in male rats either on the first day of life or after maturation did not have a significant influence on circulatory reaction to chronic normobaric hypoxia. Female rats in permanent estrus and those with ovariectomy had larger posthypoxic hypertrophy of the right ventricle as indicated by higher values for right/left ventricular weight ratio and relative weight of the right ventricle, than untreated controls.