Inhibition of DOC-salt and adrenal-regeneration hypertension with the calcium blocker nifedipine.
When nifedipine was given to rats at a dosage of 0.3 mg/kg, the blood pressure fell and heart rates rose slightly in normotensive controls, but both changes were more marked in rats with DOC-salt hypertension, the magnitude of the drop in mm Hg being progressively greater as hypertension evolved. Tachycardia also tended to increase, but became somewhat erratic once hypertension was established. Both changes were relatively constant and equivalent when expressed as a percentage of the initial value. Nifedipine given by minipump at a dosage of 8 mg/ml proved able to prevent or modulate, adrenal-regeneration hypertension, but not DOC-salt hypertension. However, in the latter, when the pumps were discontinued and a 1 mg/kg/day injection schedule was substituted, blood pressure fell in nifedipine-treated and rose in untreated rats. The latter dosage had a greater effect on blood pressure and heart rate of normotensive rats than 0.3 mg/kg.
D000311:Adrenal Glands / Q000502:physiology*; D000315:Adrenalectomy; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003900:Desoxycorticosterone / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000139:chemically induced / Q000188:drug therapy*; D006977:Hypertension, Renal / Q000188:drug therapy; D009392:Nephrectomy; D009543:Nifedipine / Q000627:therapeutic use*; D011725:Pyridines / Q000627:therapeutic use*; D051381:Rats; D011919:Rats, Inbred Strains; D012038:Regeneration
D011725:Pyridines; D003900:Desoxycorticosterone; D009543:Nifedipine