AJP - Heart and Circulatory Physiology, Vol 242, Issue 6 1000-H1009, Copyright © 1982 by American Physiological Society
Active hepatic capacitance responses to neural and humoral stimuli in dogs
T. D. Bennett, C. L. MacAnespie and C. F. Rothe
Active changes in hepatic capacitance were studied in pump-perfused dog
livers during hepatic nerve stimulation or during intrahepatic arterial
infusion of histamine (0.01-1 mg/l) or epinephrine (0.05 mg/l). Hepatic
nerve stimulation at 5 pulses/s (pps) reduced hepatic blood volume by 76
+/- 39 (SD) ml/kg tissue and decreased the apparent hepatic compliance 36%
from a control value of 25.6 +/- 9.3 ml.kg-1.mmHg-1, with constant flow
perfusion. With a constant hepatic arterial pressure, 5 pps stimulation
decreased hepatic arterial flow to 16% of control; the volume expelled was
91 +/- 33 ml/kg. Epinephrine caused hepatic artery constriction, the active
expulsion of 71 ml/kg of blood, and a decrease of about 30% in hepatic
compliance. Histamine dramatically reduced the hepatic vascular compliance,
decreased the portal venous conductance, increased hepatic arterial
conductance, and caused the apparent hepatic blood volume to double.
Increased hepatic venous pressure, hepatic nerve stimulation, epinephrine,
and, especially, histamine caused a significant filtration of fluid from
the hepatic vasculature. We conclude that significant active capacitance
changes and transsinusoidal fluid filtration can be induced in the canine
liver by neural and hormonal stimuli.
