Effects of jaundiced plasma on vascular sensitivity to noradrenalin

Alterations in renal perfusion have been shown in a variety of liver diseases. The authors have examined the possibility that the syndrome is due to a renal vascular hypersensitivity to noradrenaline (NA). Isolated perfused kidneys and segments of rabbit femoral artery were used. Potentiation of the pressor effects of injected NA occurred in all (five artery and five kidney) preparations when jaundiced baboon plasma was perfused. These changes were significant (P < 0.05) in nine out of the ten experiments. Controls to which normal baboon plasma was administered showed no such change. No correlation was found between the degree of NA potentiation and the plasma concentrations of bilirubin (total and conjugated), serum glutamic oxaloacetic transaminase, blood urea nitrogen, serum glutamic pyruvic transaminase, alkaline phosphatase, Na⁺ ions or K⁺ ions in the jaundiced plasma. Plasma renin levels were not significantly changed. When arteries were perfused with Krebs solution containing the β lipoprotein extract of jaundiced plasma, a potentiation of NA was found. Perfusion of sodium taurocholate or sodium deoxycholate (400 μg/ml) yielded no potentiation. Thus, the altered renal perfusion associated with jaundice may be attributed to a potentiated pressor response to NA which may be caused by an increased level of cholesterol carried on the β lipoprotein.