AJP - Regulatory, Integrative and Comparative Physiology, Vol 253, Issue 1 64-R70, Copyright © 1987 by American Physiological Society

ARTICLES

Acid-base status and electrolytes in red blood cells and plasma of turtles submerged at 3 degrees C

L. A. Maginniss and B. M. Hitzig

Two groups of adult Chrysemys picta bellii were studied; control turtles were maintained at 24 degrees C with free access to air, and diving animals were continuously submerged for 8.5-9.5 wk in aerated water at 3 degrees C. Cold submergence elicited a substantial lactic acidosis (blood pH 7.70; plasma [lactate-] 42.5 meq/l H2O). This acid load was largely balanced by changes in plasma strong ions; [Cl-] decreased, and [Ca2+] and [Mg2+] increased. Phosphorus nuclear magnetic resonance showed a significant reduction in the transerythrocyte pH gradient of diving animals (control, delta pH 0.66-0.90; diving, 0.00-0.11). This relative alkalosis of submerged turtle red cells was related to changes in blood cell (RBC) volume and composition; mean corpuscular concentration of hemoglobin [( Hb]) and RBC H2O content measurements revealed a 39% increase in RBC volume. Cell volume change was effected by a proportionally greater influx of K+ than Cl-, providing ionic compensation for the lactic acidosis. The obligatory H2O influx, which decreased the effective concentration of protein anion, and a 77% reduction of RBC [ATP] further contributed to the relative alkalosis. The combined effects of RBC alkalization and reduced [ATP] account for the observed Hb-O2 binding properties previously reported for submerged turtles at 3 degrees C (15).

This article has been cited by other articles:

				D. E. Warren and D. C. Jackson Effects of temperature on anoxic submergence: skeletal buffering, lactate distribution, and glycogen utilization in the turtle, Trachemys scripta Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R458 - R467. [Abstract] [Full Text] [PDF]