The effects of food restriction and exercise on site-specific differences in adipocyte volume and adipose tissue cellularity in the guinea-pig. 1. Superficial and intra-abdominal sites.

The volume and number of adipocytes were measured in fourteen anatomical sites of adult guinea-pigs kept in small cages and fed ad lib., kept in small cages and on restricted diet or fed ad lib. and exercised. In the sedentary ad lib.-fed animals, there was no significant correlation between percentage body-weight as adipose tissue, as determined by direct dissection, and mean adipocyte volume based on samples from many different sites. The correlation was significant, though not high, for sedentary, restricted-diet animals and for exercised specimens. The correlations between the volume of adipocytes from left-right pairs of sites, and from sites around the same limb, were highly significant under all conditions studied. The correlation between the volume of adipocytes from sites other than left-right pairs of sites was weaker and in some cases statistically insignificant in sedentary ad lib.-fed guinea-pigs. The volume of adipocytes from sites in the groin region, the mesenteries and medial to the trapezius muscle failed to correlate in many cases with the volume of adipocytes from other sites sampled. The number of adipocytes at each site was similar in the exercised and sedentary ad lib.-fed animals. The restricted-diet, sedentary group had fewer adipocytes at all sites studied except the omental and mesenteric fat mass and the groin sites. It is suggested that moderate regular exercise or fasting gives rise to closer coordination between adipocytes at different sites because central factors regulating adipocyte volume become more prominent than local factors.