Influence of Cortisone upon Brown Fat of Hamsters and Mice.

Abstract

1. Beyond an early age (about 3 weeks), the proportion of brown fat within the hamster maintains a relative constancy. In contrast, the ratio of white fat to body weight increases precipitously with age until full maturity of the hamster. 2. Cortisone treatment results in a prompt hypertrophy of brown fat in hamsters and mice, reflected microscopically by measurable expansion of cell diameter. White fat is possibly somewhat reduced in weight. 3. The reactive hypertrophy of brown fat in cortisone-treated hamsters diminishes with increasing age, apparently caused in part by the increasing numbers of unresponsive white fat cells within the borders of brown fat masses.