Hepatorenal baroreflex in cirrhotic rats.
Dibona, Gerald F., and Linda L. Sawin.
Department of Internal Medicine, University of Iowa College of
Medicine, and Veterans Administration Medical Center, Iowa City, IA
52242
APStracts 2:0030G, 1995.
A hepatorenal baroreflex has been described wherein increases in
intrahepatic sinusoidal pressure stimulate an intrahepatic
baroreceptor resulting in increases in afferent hepatic (HNA) and
efferent renal sympathetic nerve activity (RNA). Hepatic denervation
prevents the increase in RNA. This baroreflex is postulated to
contribute to the increase in RNA found in cirrhosis wherein
intrahepatic sinusoidal pressure is increased. However, the increased
fibrosis in the cirrhotic liver may render the intrahepatic
baroreceptor less sensitive to increases in intrahepatic sinusoidal
pressure. Using thoracic inferior vena cava constriction,
intrahepatic sinusoidal pressure (i.e. inferior vena cava pressure,
IVCP) was increased in control rats and rats with cirrhosis due to
common bile duct ligation (CBDL) while HNA and RNA were measured.
With increases in IVCP of 5 mm Hg, increases in HNA (+ 38 +/- 2 and +
44 +/- 3 %) and RNA (+ 25 +/- 1 and + 34 +/- 3 %) were not different
in control and CBDL rats, respectively. The slope gain, % _ HNA/_
IVCP, was + 7.1 +/- 0.6 and + 8.1 +/- 0.7 %/mm Hg in control and CBDL
rats, respectively. Therefore, the hepatorenal baroreflex is not
desensitized in the CBDL rat and the hepatorenal baroreflex is
capable of contributing to the increase in RNA observed in cirrhosis.
Received 19 October 1994; accepted in final form 9 February 1995.
APS Manuscript Number G424-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 7 March 1995.