Adrenocortical and bioenergetic responses to cold in five species of murine rodent

Abstract

Oxygen consumption, rectal temperature, and plasma concentrations of glucocorticoids, free fatty acids, and glucose were studied in 5 species of rodents after cold exposure that exceeded their homeostatic capability (7°C for 15 min). Adrenocortical responses and metabolic responses (oxygen consumption) to cold were large in 3 solitary, terrestrial species, dwarf hamsters (Phodopus sungorus, P. campbelli, and P. roborovskii) and were minimal in a colonial fossorial species, mole voles (Ellobius talpinus). Bank voles (Clethrionomys glareolus) showed intermediate responses. There were no interspecific differences in mobilization of main bioenergetic substrates (glucose and free fatty acids). Results are interpreted in terms of evolutionary changes of stress: reactivity was positively correlated with the rate of social stimuli and negatively correlated with physically stressful stimuli in the natural environment of the species.