Adrenergic Effects on the Oxygen Affinity and pH of Cultured Erythrocytes and Blood of the Mummichog,Fundulus heteroclitus

Abstract

Epinephrine had no effect on the blood O₂ afinity of Fundulus heteroclitus in the presence of low CO₂ (1.5 mmHg Pco₂). However, it did increase O₂ afinity proportionately with increasing Pco₂. Erythrocytes in NaHCO₃-buffered Bull saline gave results that were virtually identical to those obtained with blood. This was not the case for erythrocytes in synthetically buffered Bull salines. Their O₂ afinity was markedly lower than that of blood, regardless of the CO₂ concentration, presence of epinephrine or bovine serum albumin, or type of synthetic buffer (Hepes, Tris, Bis-Tris) employed. Thus, conclusions drawn from studies utilizing synthetically buffered salines may be misleading Epinephrine stimulated proton effux, resulting in an increase of the intracellular pH from erythrocytes in Hepes-buffered Bull saline. This appears to be an artifact resulting from the use of Hepes, as it was not observed in blood. The intracellular pH of both blood and erythrocytes in NaHCO₃-buffered Bull saline was insensitive ...