Metabolic and cardiac responses to temperature in the lizard Dipsosaurus dorsalis
Citation
George A Bartholomew, and William R Dawson, Metabolic and cardiac responses to temperature in the lizard Dipsosaurus dorsalis: .
Summary
It is well known that lizards when active can maintain body temperature at a characteristic level by behavioral means (Cowles and Bogert, 1944). The fact that this level may be the same in species of the same genusoccurring in markedly different climates but may differ by several degrees in sympatric species of different genera (Bogert, 1949) implies that physiological adjustments to particular body temperatures exist in lizards and that these adjustments may differ from group to group. In an initial attempt to understand the nature and significance of these physiological adjustments, we have elected to examine oxygen consumption and in vivo and in vitro cardiac performance. These have been selected because (1) total oxygen consumption [...]
Summary
It is well known that lizards when active can maintain body temperature at a characteristic level by behavioral means (Cowles and Bogert, 1944). The fact that this level may be the same in species of the same genusoccurring in markedly different climates but may differ by several degrees in sympatric species of different genera (Bogert, 1949) implies that physiological adjustments to particular body temperatures exist in lizards and that these adjustments may differ from group to group. In an initial attempt to understand the nature and significance of these physiological adjustments, we have elected to examine oxygen consumption and in vivo and in vitro cardiac performance. These have been selected because (1) total oxygen consumption furnishes an integrated statement of total physiological activity; (2) cardiac performance is of primary importance in the adjustment of the circulatory system to the metabolic demands associated with high temperature; and (3) in vitro measurements of the effects of temperature on auricular rate and ventricular contraction provide indications of the degree to which individual tissues share in the temperature adaptation of the intact animal.
Published in Physiological Zoology, volume 31, issue 2, on pages 100 - 111, in 1958.