Effects of angiotensin and noradrenaline on discharge in fibres of the cervical sympathetic nerve in cats and dogs.

1. The effects of angiotensin and noradrenaline on discharge frequency in single and few-fibre preparations of the cervical sympathetic nerve of cats and dogs have been compared.2. When equal changes in blood pressure were produced by intravenous infusion of these drugs, the changes found in sympathetic discharge were similar both in anaesthetized animals and in a decerebrate one.3. Angiotensin and noradrenaline also have similar effects on discharge in sympathetic nerve fibres following complete denervation of the baroreceptor and chemoreceptor nerves.4. It is concluded that when the blood pressure is raised to 200 mmHg by angiotensin, the drug has no central stimulant action on the sympathetic nervous system.