STUDIES ON VEM AND VDM IN BLOOD IN RELATION TO RENAL HEMODYNAMICS AND RENAL OXYGEN EXTRACTION IN CHRONIC CONGESTIVE HEART FAILURE 12

Abstract

In 10 patients in chronic congestive failure, due to rheumatic valvular disease, the renal blood flow was reduced about 70%, glomerular filtration rate was reduced about 50% and the renal PAH extraction was normal. As compared to a control group of non-cardiac patients,the cardiacs had an increased renal extraction of oxygen (mean renal A.V. O2 difference = 3.53 vs. 1.29 vol. %) and a decreased renal oxygen consumption (mean = 12 vs. 15.8 cc. per min. per 1.73 m.2) and a reduced calculated mean renal oxygen tension. By the rat mesoappendix method, high titers of vasoexcitor material (VEM) were demonstrated in the renal venous blood in 10 of 12 subjects in congestive failure, in contrast to the trace of VEM found in 3 of the 13 controls. It is suggested that decreased oxygen tension in renal interstitial fluids may be responsible in part for the release of VEM in the cardiacs, because of in vitro evidence and the observation that inhalation of a 10% oxygen mixture for 15 min. was associated with increased VEM titers in the renal vein blood of 2 normal subjects, in whom the renal oxygen consumption and oxygen extraction remain constant. High titers of vasodepressor material (VDM) were found in the hepatic venous blood of 10 of 11 cardiacs, whereas only mild VDM reactions were present in hepatic venous blood of 3 of the 14 control subjects. Hepatic venous oxygen saturation was markedly reduced in all the cardiacs. Peripheral arterial blood which contained a mixture of VEM and VDM in the cardiacs, showed a predominance of VEM in 5, predominance of VDM in 4 and a neutral response in 2 of the subjects in congestive failure as compared to that of the 13 controls, in all of whom a neutral reaction was present. The relationship between VEM production by the ischemic, hypoxic kidney and the marked renal vaso-constriction in congestive heart failure remains to be detd.