Effect of aldosterone and of plasma extracts on a rat heart-lung preparation

¹ Department of Physiology, Western Reserve University School of Medicine, Cleveland, Ohio

Heart-lungs from intact rats were perfused with blood from intact rats (intact-intact preparations) or with blood from adrenalectomized rats (intact-adrenalectomized preparations). Left ventricular work index (LVWI) was employed to evaluate performance of the heart-lung and calculated as the product of cardiac output and mean arterial blood pressure. In confirmation of a previous report from this laboratory, LVWI was less for intact-adrenalectomized preparations than for intact-intact preparations. Aldosterone, added to perfusion blood from adrenalectomized rats to make a concentration of 2 x 10^–3, 8 x 10^–3 or 3.2 x 10^–2 µg/100 ml, increased LVWI of the intact-adrenalectomized preparation to that of the intact-intact preparation. Extracts of plasma from intact rats, which may be expected to contain corticosteroids, were also capable of increasing LVWI of the intact-adrenalectomized preparation. Extracts of plasma from adrenalectomized rats were inactive.