Changes in brown adipose tissues and coxsackievirus B pathogenesis in mice on acute and chronic cold exposure.

Abstract

On acute cold exposure the normal brown adipose cells in the mouse interscapular pad underwent morphological changes apparently as a result of loss and redistribution of the intracellular lipid globules; on continued cold exposure the globules increased in numbers and size. If adult female mice were inoculated with coxsackievirus B-3 during acute cold exposure and returned to normal room temperature soon afterwards, the viral damage in the brown adipose tissues was seriously aggravated; if on the other hand they were left in the cold for the duration of the infection, the damage was aggravated to a lesser degree. Finally, if cold-acclimated mice were inoculated the lesion was localized in one area of the pad.In contrast, the myocardial damage was aggravated only in those mice which were inoculated during acute cold exposure and left in the cold. The cox. B-3 pathogenesis in the brain showed no clear-cut variations resulting from changes in the ambient temperature. The infectious amount of virus recovered from the heart and brain appeared to be greater and persist longer, if the mice were subjected to a prolonged cold exposure.The cold exposure, however, failed completely to increase the age susceptibility of mice to cox. B-2.