Lactate dehydrogenase in diving animals — A comparative study with special reference to the eider ( Somateria mollissima)

Abstract

1. 1. The isoenzyme pattern in brain, heart and skeletal muscle of some diving animals, the seal and the eider, were compared to a non-diving animal, the sheep, by disc electrophoresis. The quantitation of the isoenzymes were made by densitometry. 2. 2. In contrast to the sheep which showed an isoenzyme pattern similar to the usual findings on non-diving animals all isoenzymes were relatively abundant in all tissues examined in the seal. 3. 3. The enzyme from the same tissues of the eider did not separate either at pH 8·3 or at pH 7·4 and 9·3. Thus only one “band” coinciding with that of LDH 5 of the seal and sheep was obtained. 4. 4. It is concluded that biochemical adaptations on enzyme level are taking place as response to the hypoxic conditions induced upon prolonged diving.