Hemodynamic Changes in Hypophysectomized Rats
The following changes were observed in hypophysectomized rats, 14 days after the operation: greatly reduced cardiac output, bradycardia, slight increase in total peripheral resistance, less work done by the left ventricle, low blood pressure, reduced respiratory rate and oxygen uptake, no change in blood volume and erythrocyte count. During an increased input or resistance load, the output and work of the heart rose greatly both in normal and in hypophysectomized rats. The maximum work which the heart did under these conditions, especially if the size of the heart was taken into consideration, was not significantly less in hypophysectomized than in normal rats. It is concluded that the low cardiac output after hypophysectomy is not primarily of cardiac origin.
- Received June 1, 1959.
- © 1959 American Heart Association, Inc.