The effect of pentobarbitone on plasma and intracellular sodium, potassium and pH in rabbit cardiac and skeletal muscle.

1. Pentobarbitone anaesthesia, in rabbits, produces (i) hypokalaemia, (ii) increased intracellular potassium and reduced intracellular sodium in cardiac and skeletal muscle. 2. These changes suggest that the hypokalaemia which accompanies anaesthesia results from movement of potassium between the extracellular and intracellular compartments.