The influence of hepatic portal circulation on urine flow

1. A study of the effect of changes in the hepatic portal venous pressure (HPVP) on the rate of urine flow in dogs has been made. Normally this pressure varies between 3.7 and 14.9 cm H(2)O. It can be raised or lowered by varying the method of manipulation of the visceral organs.2. When the HPVP was raised within 15 cm H(2)O above the premanipulation level it caused an increase in urine flow to 2-3 times the normal levels within 2-5 sec. If the HPVP was raised to more than 15 cm H(2)O above the pre-manipulation levels it resulted in a period of antidiuresis. The urine flow returned rapidly to normal level immediately after the pressure was released.3. The kidney volume increased when an induced diuresis occurred and decreased when an antidiuresis occurred.4. The urine chloride concentration decreased during diuresis, but total chloride excretion increased. Total chloride excretion was reduced when an antidiuresis occurred.5. Topical application of local anaesthetics at the hilus of the kidney and on the renal nervous plexus abolished the response. This and other evidence indicate that this effect on urine flow is a result of nervous reflex activity, probably involving the sympathetic but not the vagus.6. The receptive area lies in the mesentery between the mesenteric capillaries and the main portal vein.