Effect of Epinephrine on the Renal Circulation

Abstract

The presence in malignant tumors of blood vessels which are atypical in appearance and at times extraordinarily profuse in number has been demonstrated frequently. Such “malignant” vessels have been studied in detail in brain tumors, but their presence in other areas, particularly in carcinomas of the kidney, has been thoroughly substantiated. Tumor vessels have also been noted on occasion in carcinoma of the stomach, pancreas, bladder, and liver. That these tumor vessels may carry an extraordinarily large amount of blood has frequently been demonstrated by serial angiography. That their pattern of arborization and their randomness of distribution need bear no similarity to that of normal vessels is apparent from accumulated roentgen data. It has been shown by microscopic and microangiographic studies that malignant tumors are supplied by both normal preformed vessels and by embryonic vessels, the walls of which are devoid of elastic tissue (3). There is suggestive evidence that these vessels are not responsive to humoral agents which characteristically affect normal blood vessels (2), although this has not received corroboration from microcirculatory studies (6). In an analysis of a group of renal neoplasms, an effort to demonstrate the vessels supplying them more dependably, more sharply, and with smaller volumes of contrast agent, seemed worth exploring. If it were feasible to narrow adjacent normal vessels by humoral agents, without affecting the tumor vessels to the neoplasm, then a redistribution of contrast agent might very well be accomplished. By the same token, if vasoconstriction of normal vessels were attained in the presence of persistently dilated tumor vessels, then it might be possible to perfuse a regional vascular bed with a chemotherapeutic agent which would be selectively distributed in higher concentration to the tumor area than to the surrounding normal tissues. In order to assess the response of tumor vessels to pharmacologic agents in clinical or experimental situations, the effect of these agents on normal vessels must be known and demonstrable. As a first step in exploring this problem, it was necessary to determine the effects of specific pharmacologic agents on the renal vessels, the extent to which these effects were visible, and the feasibility of effective comparisons with baseline normal studies. Methods and Material Six mongrel dogs were studied in 22 different experiments. Percutaneous transfemoral aortic catheterization was usually employed, with the Seldinger technic (13), although occasionally open surgical cut-down and catheter passage were undertaken. In some instances, selective renal arterial injection was performed, while in others the catheter was in the aorta adjacent to the orifices of the renal arteries. Anesthesia was accomplished with intravenous Nembutal in a dose of 30 mg. per kilogram.