Cutaneous and renal responses to intravascular infusions of HCl and NH 4Cl in the bullfrog ( Rana catesbiana)

Abstract

1. 1. This study examined the ability of bullfrogs to correct a non-respiratory acidosis by renal and cutaneous mechanisms. 2. 2. Acidosis was induced by intravascular infusions of HCl (3 mmole/kg) or NH 4Cl (4 mmole/kg). 3. 3. The acid load was removed primarily by increased renal excretion of NH 4 +, while urine pH and titratable buffer acid excretion changed little. 4. 4. Acid loading resulted in an increase in cutaneous permeability, shown by large ion losses and elevated water uptake across the skin. 5. 5. It is concluded that infused mineral acids were immediately buffered by the extracellular fluids, moved rapidly into the intracellular fluid compartment, and only later were slowly cleared.