[Clinical and experimental investigations of the effect of dopamine on haemodynamics and function of kidney and liver (author's transl)].

Increased incidence of renal insufficiency is observed in severe damage of liver parenchyma such as fulminant hepatitis, decompensated cirrhosis of the liver, septic cholangitis and the different forms of obstructive jaundice. Functional circulatory disturbances of the kidney, especially of the renal cortex, are of importance in the aetiology of this condition. Dopamine, at a dosage as low as 3 gamma/kg/min leads to an improvement in renal blood flow and also to an increase in hepatic blood flow. These observations are of therapeutic importance. Some important circulatory and functional parameters of both these organs, which influence each other under normal and pathological conditions, were studied in the presence of dopamine and the following results were obtained: 1. An investigation of the intrarenal haemodynamics with 133 Xenon in patients with severe cirrhosis of the liver and in patients with obstructive jaundice resulted in an increase of 91% in the mean renal blood flow. The blood flow in the renal cortex increased by 36.2% and in the renal medulla 18.5%, whereas the renal fat tissue showed no change. Compartment I, which was diminished as compared with the control value, also increased. The percentage contribution of the mean renal blood flow and the blood flow of the renal cortex towards the cardiac output was greater under the influence of dopamine; hence a greater part of the cardiac output flows into the kidney under dopamine. 2. The glomerular filtrate and the renal plasma flow increased under dopamine (13.5% and 43.1%, respectively). The increase was greater in compensated than in decompensated cirrhosis. In patients with obstructive jaundice there was a smaller increase in both these parameters than in patients with cirrhosis in the presence of dopamine. No connection was found between the increase in renal plasma flow with dopamine and the blood levels of bilirubin, cholinesterase, GOT and the Normotest. 3. The urinary output of sodium increased by 191.4% with dopamine. Patients with an initial renal plasma flow value of over 300 ml/min had a higher sodium output. These patients also eliminated more sodium under the influence of dopamine than those with an initial renal plasma flow value of under 300 ml/min. 4. Blood flow determinations in the portal vein and the hepatic artery in man, obtained during operation, showed an increase in portal flow of 28.5% and hepatic artery flow of 6.3% in response to dopamine. The percentage contribution of portal blood flow towards the cardiac output increase on dopamine administration. The functional hepatic blood flow, analyzed with 131-J-BSP, did not change. The wedged hepatic vein pressure, which is a good measure of portal pressure, increased on average by only 7% with dopamine at a dosage of 3 gamma/kg/min, but by 20.3% with twice the dosage. Dopamine did not cause a change in hepatic blood volume; hence, blood sequestration in the liver can be excluded in response to the dopamine-evoked increase in portal blood flow. 5...