Effect of temperature on water and ion balance in larval Ambystoma gracile

1. 1. Larval Ambystoma adapted to 5, `5 and 25°C maintain a steady state with respect to water, sodium and chloride content. 2. 2. The uptake of water, which equals the renal loss of water, was 0·03, 0·11 and 0·20 ml/10g per hr at 5, 15 and 25°C respectively. 3. 3. The GFR at 5, 15 and 25°C was respectively 0·9, 0·33 and 0·36 ml/10 g per hr. 4. 4. The sodium efflux at 5, 15 and 25°C was 0·6, 1·4 adn 2·7 μequiv./10 g per hr. The renal fraction of the efflux was 17 per cent at 5°C, 21 per cent at 15°C and 33 per cent at 25°C.