Effect of vertebral, carotid and intravenous infusions of lysine vasopressin on plasma vasopressin and cardiovascular function.

The cardiovascular and vasopressin-releasing effects of vertebral artery, carotid artery and intravenous (i.v.) infusions of lysine vasopressin (150 microU/kg X min) were studied in anesthetized dogs. Vertebral and carotid artery infusions of lysine vasopressin led to similar decreases in cardiac output as i.v. infusions. Heart rate, however, decreased to a greater extent with vertebral and carotid artery infusions of lysine vasopressin than i.v. infusions. There were no changes in either mean arterial blood pressure or the plasma vasopressin concentration. The results indicate that peripheral vasopressin: has a central effect to reduce heart rate; has a peripheral effect on the heart to reduce cardiac output, and probably does not feed back to inhibit its own release.