Effects of H2-receptor antagonists on plasma aldosterone response to angiotensin II in healthy subjects; (II). Comparison of cimetidine and ranitidine.
The effects of H2-receptor antagonists, cimetidine and ranitidine, on plasma aldosterone response to angiotensin II (AII) were examined in six healthy subjects. The study was carried out on three different occasions with a two week interval. Cimetidine (400 mg), ranitidine (150 mg) or a placebo was given orally every 12 hours for 3 days in a double-blind, cross-over, double-dummy design. On the fourth day, 1 hour after the final (seventh) administration of the same agent, furosemide (20 mg) was injected intravenously. The plasma levels of renin activity (PRA), AII and aldosterone (PA) were determined for a 120 minute period after furosemide. PRA, AII and PA increased after furosemide with as well as without H2-receptor antagonist. The basal and stimulated levels of these parameters were not significantly different at any observation point among the three regimen groups. A significant correlation was observed between AII and PA with placebo (P less than 0.01) and ranitidine (P less than 0.01), but not with cimetidine (P greater than 0.05). The slope of the regression line with ranitidine was not significantly different from that of the placebo. These data indicate that the PA response to AII is blunted by cimetidine, but not by ranitidine. The current study supports the idea that this blunted response during cimetidine is independent of the blockade of H2-receptor.
Fujimura
A
A
Department of Clinical Pharmacology, Medical College of Oita, Japan.
Ohashi
K
K
Sudo
T
T
Sakamoto
K
K
Oka
T
T
Ebihara
A
A
D000284:Administration, Oral; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D000450:Aldosterone / Q000097:blood*; D000804:Angiotensin II / Q000097:blood*; D001794:Blood Pressure; D002927:Cimetidine / Q000494:pharmacology*; D004311:Double-Blind Method; D005665:Furosemide / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D008297:Male; D011188:Potassium / Q000097:blood / Q000652:urine; D011899:Ranitidine / Q000494:pharmacology*; D012083:Renin / Q000097:blood; D012964:Sodium / Q000097:blood / Q000652:urine; D013997:Time Factors
D000804:Angiotensin II; D000450:Aldosterone; D005665:Furosemide; D002927:Cimetidine; D011899:Ranitidine; D000324:Adrenocorticotropic Hormone; D012964:Sodium; D012083:Renin; D011188:Potassium