Effect of Synthetic Angiotonin on the Carotid Sinus

Natural decapeptide or synthetic octapeptide angiotonin was ineffective in lowering arterial pressure or decreasing the carotid occlusion response when injected into the carotid sinus adventitia. Injection of synthetic octapeptide angiotonin into the lumen of the carotid sinus after tying its branches decreased the carotid occlusion response but the effect depended on dosage many times the pressor activity of 1 γ of norepinephrine which elicited a comparable effect.