Role of catecholamines in angiotensin induced hyperglycaemia

The effects of angiotensin II were studied on blood sugar level in dogs. Intracerebroventricular administration of pressor dose of angiotensin caused a rise in blood sugar level. The hyperglycaemia and pressor response was not affected by bilateral vagotomy and was less marked in adrenalectomized dogs. The hyperglycaemic effect and pressor response was not observed in reserpinized and spinal vagotomized dogs. It is suggested that centrally administered angiotensin stimulates the hypothalamic or medullary accelerator neurons (central sympathetic structures) to cause a marked release of catecholamines from peripheral stores specially adrenal medulla. This excessive release of catecholamines is responsible for hyperglycaemia and pressor response of angiotensin II in dogs.