Effects of propranolol on venous compliance in conscious rats with pre-hepatic portal hypertension.
OBJECTIVE
The venous system is the primary capacitance region in the body. However, the influence of active changes in the venous system on the hemodynamic alterations of portal hypertension is poorly understood. To investigate venous compliance (VC) in conscious partial portal vein ligated rats (PPVL) and the effect of propranolol on VC.


METHODS
Venous compliance was derived from the relationship between changes in mean circulatory filling pressure (MCFP) and changes in blood volume (BV). Measurements were performed before and after i.v. propranolol (7.5 mg/Kg) or placebo in rats with portal hypertension due to PPVL and sham operated controls.


RESULTS
PPVL rats had an increased VC when compared to Sham (4.9+/-1.4 vs. 3.7+/-0.9 ml kg-1 mm Hg-1; P<0.02). VC did not change after placebo but was significantly reduced by Propranolol in PPVL (-32.9+/-15.7%; P<0,007). Propranolol did not modify venous compliance in sham operated rats (+10.9+/-13.4%; P=ns).


CONCLUSIONS
Venous compliance is increased in portal hypertensive rats, suggesting that the venous system contributes to the profound circulatory changes encountered in portal hypertension. The increased venous compliance is markedly attenuated by propranolol, suggesting that this abnormality is related to increased adrenergic activity.
Hepatic Hemodynamic Lab., Liver Unit, Institut Clínic de Malalties Digestives i Metabolisme, Hospital Clínic de Barcelona, Institut de Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.
Victoria
V
Andreu
Juan-Carlos
JC
Garcia-Pagan
Raffaela
R
Lionetti
Carlos
C
Piera
Juan G
JG
Abraldes
Jaume
J
Bosch
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003187:Compliance / Q000187:drug effects; D006975:Hypertension, Portal / Q000503:physiopathology*; D008297:Male; D011169:Portal Vein / Q000187:drug effects*; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014665:Vasodilator Agents / Q000494:pharmacology*
D014665:Vasodilator Agents; D011433:Propranolol