Experimental conditions have been established for the operation of a rat heart-lung preparation which result in a high degree of uniformity of work performance as measured by left ventricular work index (LVWI) (proportional to the product of cardiac output and mean arterial blood pressure). At a pcrfusion blood temperature of 37° C heart rate was higher and left ventricular work index lower than at 32° C. Peripheral resistance was adjusted to give an analysis of the work performance of the heart-lung at three different levels of mean arterial blood pressure: 80, 110, and 130 mm. Hg. The lower the pressure, the greater LVWI. Heart rate was not influenced by alterations in peripheral resistance. LVWI was less in heart-lung preparations perfused with blood from adrenalectomized rats than in preparations perfused with blood from intact rats. Corticosterone, cortisol or aldosterone was added to perfusion blood from adrcnalectomized rats to yield a concentration of 10μg., 10 μg. and 3.2×10−2 μg. per 100 ml., re...
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Sayers et al. (1960) studied this question.