Cardiovascular responsiveness to vasoactive agents in rats with obstructive jaundice.

1. Pressor responses to tyramine, beta-phenylethylamine and angiotensin II were normal in urethane-anaesthetized rats 7 days after division of the common bile duct. The pressor response to noradrenaline was enhanced at the highest dose level used. 2. The hypotensive response to haemorrhage was exaggerated in bile duct divided rats. 3. The exaggerated haemorrhagic hypotension of bile duct divided rats is unlikely to be the result of impaired vascular response to noradrenaline or angiotensin II, or of accumulation of false neurotransmitters by sympathetic nerves.