A simple method to determine fat cell size and number in four mammalian species.

Abstract

DI GIROLAMO, MARIO, SHELDON MENDLINGER, AND JOHN W. FERTIG. A simple method to determine fa t cell size and number in four mammalian species. Am. J. Physiol. 221 (3) : 850458. 1971 .-Adipose tissue from various fat depots in four mammalian species was characterized in terms of mean fat cell size (diameter and volume), relative dispersion in fat cell size, and fat cell number by a method based on direct microscopic determination of the diameter of isolated fat cells. The degree of precision of the various operations involved and of the final estimates of fat cell size and number were evaluated and found to be within acceptable limits. The morphology of the adipose cells was studied in ad libitum-fed rats, hamsters, guinea pigs, and dogs at different stages of development. In each species, enlargement of the fat cells in a given adipose depot led to fat cell populations that were more homoqenous in size. In the rat, at an earlier stage of development (2 mdnths of age), considerable interdepot differences were found with regard to fat cell size and number in four different locations of the adipose organ. These findings indicate the general applicability of this methodology to the characterization of adipose tissue in mammalian species. In addition, this study suggests that heterogeneity in size of a fat cell population is a measurable parameter which should further as a guide to the expansion of the adipose organ. be studied