Effects of cortisol on gill chloride cell morphology and ionic uptake in the freshwater trout,Salmo gairdneri

Daily intramuscular injection of cortisol (4 mg kg−1 body weight) in rainbow trout,Salmo gairdneri, for 10 days caused significant increases in the number and individual apical surface area of gill chloride cells per mm2 of filament epithelium. Concomitantly, whole body influxes of sodium (Na+) and chloride (Cl−) increased. Acute (3 h) intra-arterial infusion of cortisol did not affect whole body Na+ or Cl− influx. A significant correlation was …