Surviving extreme lactic acidosis: the role of calcium lactate formation in the anoxic turtle.
During prolonged anoxia at low temperature, freshwater turtles develop high plasma concentrations of both lactate and calcium. At these concentrations the formation of the complex, calcium lactate, normally of little biological significance because of the low association constant for the reaction, significantly reduces the free concentrations of both lactate and calcium. In addition, lactate is taken up by the shell and skeleton to an extent that strongly indicates that calcium lactate formation participates in these structures as well. The binding of calcium to lactate thus contributes to the efflux of lactic acid from the anoxic cells and to the exploitation of the powerful buffering capacity of the shell and skeleton.
Jackson
Donald C
DC
Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, RI 02912, USA. donald.jackson@brown.edu
D000140:Acidosis, Lactic / Q000401:mortality / Q000503:physiopathology*; D000222:Adaptation, Physiological; D000818:Animals; D001842:Bone and Bones / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D017610:Calcium Compounds / Q000378:metabolism*; D006801:Humans; D000860:Hypoxia / Q000378:metabolism*; D007773:Lactates / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism; D008954:Models, Biological; D014426:Turtles
D017610:Calcium Compounds; D007773:Lactates; C110051:calcium lactate; D019344:Lactic Acid; D002118:Calcium