Interrenal function in larval Ambystoma tigrinum. III. Acid-base balance responses.
Larval Ambystoma tigrinum (59-199 g) were treated with the drug aminoglutethimide (6 mg/day) in order to abolish steroid hormone synthesis. Steroid deprivation prevented the increase in plasma aldosterone concentration observed in sham-infused larvae during respiratory acidosis. It also blocked the normal compensatory response to respiratory acidosis of elevated plasma [HCO3-] and inhibited cutaneous Na+ transport. Aldosterone (10 micrograms/day) and, to a lesser extent, corticosterone (240 micrograms/day) restored the compensatory response. Aldosterone replacement also stimulated cutaneous Na+ transport in AG-inhibited larvae. The results suggest that aldosterone, at about 1000 pg/ml, supports the compensatory ionic responses to respiratory acidosis in this species.
Biological Sciences Department, California State Polytechnic University, Pomona 91768.
E M
EM
Aguiniga
D F
DF
Stiffler
D000136:Acid-Base Equilibrium / Q000187:drug effects / Q000502:physiology*; D000142:Acidosis, Respiratory / Q000209:etiology / Q000503:physiopathology; D000450:Aldosterone / Q000097:blood / Q000494:pharmacology / Q000502:physiology*; D000557:Ambystoma / Q000097:blood / Q000502:physiology*; D000616:Aminoglutethimide / Q000494:pharmacology*; D000818:Animals; D006935:Hypercapnia / Q000503:physiopathology; D007814:Larva / Q000187:drug effects / Q000502:physiology; D012016:Reference Values; D012979:Sodium Radioisotopes
D012979:Sodium Radioisotopes; D000616:Aminoglutethimide; D000450:Aldosterone