Blood pressure response to an angiotensin II antagonist in thyrotoxic patients with and without high blood pressure.
An angiotensin II antagonist, [sacrosine1, isoleucine8] angiotensin II, was infused into thyrotoxic patients. Blood pressure was monitored before and during the infusions to investigate whether the renin-angiotensin-aldosterone system was involved in the maintenance of blood pressure in normotensive and hypertensive thyrotoxic patients. Five out of 17 normotensive patients with hyperthyroidism showed more than a 10 mmHg decrease in mean blood pressure in response to the infusion (responders), while the remaining 12 patients showed no substantial change in blood pressure (non-responders). The infusion caused little change in blood pressure in 8 hyperthyroid patients with systolic hypertension. The mean levels of serum thyroxine, triiodothyronine, plasma renin activity and plasma aldosterone concentration in the normotensive responders were significantly higher than the values in the normotensive non-responders. There were no significant differences in these laboratory values between the hypertensive patients and the normotensive non-responders except that serum triiodothyronine levels were significantly higher in the hypertensive patients. The present study indicates that increased activity of the renin-angiotensin-aldosterone system is involved in the maintenance of blood pressure in most normotensive patients with severe hyperthyroidism, while hypertension in patients with hyperthyroidism is not angiotensin II dependent.
D015059:1-Sarcosine-8-Isoleucine Angiotensin II / Q000494:pharmacology; D000293:Adolescent; D000328:Adult; D000804:Angiotensin II / Q000037:antagonists & inhibitors*; D001794:Blood Pressure / Q000187:drug effects*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology*; D006980:Hyperthyroidism / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged
D000804:Angiotensin II; D015059:1-Sarcosine-8-Isoleucine Angiotensin II