Studies on the Intermediary Carbohydrate Metabolism of Aquatic Animals

Abstract

The differences and similarities between aquatic and terresfial mammals have been the subjects of several investigations (1-3). Studies of the gross and hlstologic anatomy of the lungs of several marine mammals have disclosed some structural modifications peculiar to these species (4, 5). The problems of adaptation of physical structure to an aquatic environment have been discussed by Kellogg (6) and the physiology of respiration of diving animals has been reviewed by Irving (7).The mechanisms for controlling the oxygen supply to the tissues and the ability of many marine mammals to undergo long periods of submergence have been of great interest. Irving, Scholander, and Grinnell (8) studied the respiration of dolphins during rest and diving and found that the resting oxygen consumption was less than that for seals but somewhat greater than for man per unit of weight. They reported that the lactic acid content of the muscle tissue of dolphins did not change significantly during the dive and that blood lactate values were not altered during or after diving, in contrast to the results obtained on rats and ducks (9) and on seals (8) in which lactic acid increased in the muscle during diving and in the blood during recovery.With some information on the over-all physiology of the dolphin at hand, it was of interest to study the intermediary cellular metabolism, since fundamental differences in the metabolism of aquatic and terrestial mammals must certainly reflect variations in enzymatic processes. Except for the findings of Manery, Welch, and Irving (10) that excised seal skeletal muscle can glycolyze to the same extent as rabbit muscle, data on the concentrations of the intermediates of glycolysis and on the respiratory and glycolytic enzymes in the

Historical Perspectives: History of Veterinary Medicine and Marine Mammals: A Personal Perspective

“…These scientists published a wealth of entirely new information about the living dolphin. Among the early publications that were highly useful to me were those of DuBois et al (1940), Fetcher & Fetcher (1942, Eichelberger et al (1940a, 1940b, 1940c.…”