Red cell function of carp (Cyprinus carpio) in acute hypoxia.

The red cell function of carp, subjected to acute hypoxia, was studied. During hypoxic exposure red cell water content, sodium and chloride concentration and pH increased, whereas plasma sodium and chloride concentrations decreased. Treatment of the animals with a beta-adrenergic antagonist, propranolol, before the onset of hypoxia, largely inhibited the increase in red cell water content, diminished the changes in red cell pH and prevented the changes in red cell and plasma sodium concentration. The red cell chloride concentration increased also in propranolol-treated animals thus illustrating the effect of the deoxygenation of haemoglobin on the ion concentrations of red cells. These data indicate that adrenergic activation of sodium/proton exchange across red cell membrane plays a role in the acute responses of carp to hypoxia.