Brown adipose tissue activity and oxygen consumption after scald injury in the rat

Scald injury (30% surface scald) in the rat caused rapid (1-3 h) and transient decreases in oxygen consumption (VO2 20%), colonic temperature (1.1 degree C), and brown adipose tissue (BAT) thermogenic activity (22%). Three days after injury, VO2 was slightly increased in injured rats, and sympathetically mediated heat production (assessed from the inhibitory effect of a beta-adrenergic antagonist on VO2) was significantly greater than than for controls. At this time, BAT activity (in vitro mitochondrial GDP binding) was 35% higher in injured than control rats. Food intake was inhibited for only 24 h in injured animals, but weight gain was suppressed for at least 3 days. The data indicate that sympathetic modification of BAT thermogenesis may contribute to the changes in metabolic rate and body weight gain after scald injury in the rat.