Acidosis inhibits the hypocalcemic effect of acetazolamide.
The effect of acetazolamide on calcium metabolism was examined using sham-operated, ureter-ligated and nephrectomized rats. Acetazolamide doses from 10 to 500 mg/kg produced significant hypocalcemic effects in ureter-ligated and nephrectomized rats. However, doses of acetazolamide up to 1000 mg/kg were devoid of hypocalcemic activity when administered to sham-operated rats. Sham-operated rats exhibited an acidotic response to acetazolamide while ureter-ligated rats did not. Attenuation of this drug-induced acidotic response with i.p. injections of tris(hydroxymethyl)amino-methane uncovered a hypocalcemic effect of acetazolamide in sham-operated rats. Also, the hypocalcemia associated with acetazolamide treatment of ureter-ligated rats was negated when an acidosis was induced by prior injection of NH4Cl. These data indicate that the administration of inhibitors of carbonic anhydrase produces a hypocalcemia when a metabolic acidosis is not present.
D000086:Acetazolamide / Q000097:blood / Q000494:pharmacology*; D000138:Acidosis / Q000097:blood*; D000818:Animals; D002118:Calcium / Q000097:blood*; D005260:Female; D006863:Hydrogen-Ion Concentration; D009392:Nephrectomy; D010280:Parathyroid Glands / Q000502:physiology; D051381:Rats; D013997:Time Factors; D014513:Ureter / Q000502:physiology
D000086:Acetazolamide; D002118:Calcium