In vitro effects of pH and hemoglobin-oxygen saturation on plasma and erythrocyte K+ levels in blood from trout.
Plasma and erythrocyte K+ were monitored during storage and tonometry of blood samples taken from resting rainbow trout, Oncorhynchus mykiss. During storage of arterial blood samples, plasma K+ concentration increased by 38% in 12 min. During extended tonometry of blood with a pH near 7.9 and full hemoglobin-bound oxygen (HbO2) saturation the erythrocytes showed a net loss of K+. Plasma K+ concentration increased from 2.9 mM to a near steady-state value of 5.6 mM. When tonometered at a pH near 7.2 and a HbO2 saturation at approximately 4% the erythrocytes took up K+, leading to a dramatic reduction in plasma K+ concentration to 0.2 mM. This net uptake was stimulated by isoprenaline and was inhibited by ouabain. It is concluded that net erythrocyte K+ uptake and loss can be induced in trout by changes in blood pH or HbO2 saturation in vitro.
Nielsen
O B
OB
Department of Zoophysiology, University of Aarhus, Denmark.
Lykkeboe
G
G
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D010100:Oxygen / Q000097:blood; D010949:Plasma / Q000378:metabolism; D011188:Potassium / Q000097:blood*; D014337:Trout / Q000097:blood*
D006454:Hemoglobins; D010042:Ouabain; D007545:Isoproterenol; D011188:Potassium; D010100:Oxygen