Canadian journal of physiology and pharmacology
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Can. J. Physiol. Pharmacol. · Oct 1989
Hemodynamic effects of a combination of clonidine and propranolol in conscious cirrhotic rats.
The hemodynamic effects of the combination of clonidine and propranolol were studied in conscious rats with portal hypertension owing to secondary biliary cirrhosis. Pressure and blood flow measurements (radioactive microsphere method) were performed in three groups of eight rats before and after drug administration. The combined effects of clonidine (2 micrograms/100 g body wt., i.v.) and propranolol (0.2 mg/min for 10 min) were compared with those observed after administration of either clonidine alone or propranolol alone. ⋯ These findings indicate that the combination of clonidine and propranolol is more effective for reversing splanchnic hemodynamic changes than clonidine alone or propranolol alone. The additive effects of this association are in agreement with the action of clonidine and propranolol at different levels (central and peripheral) and on different receptors (alpha and beta). It suggests that an increase in sympathetic activity may play a major role in hemodynamic changes observed in experimental cirrhosis.