Fat cell size in various body region. A statistical analysis in Equus caballus.

In 13 horses from both sexes, between 5 months and 18 years of age, in good nutritional state, statistical evaluations of fat cell sizes were performed in 16 body regions. From direct and indirect measurements referred to the cell diameter and cell number in equivalent areas, carried out on sections from paraffin embedded material and on preparations of dissociated whole cells, it emerged that the adipose cells of the subserous fat of the abdominal floor are consistently the largest, whereas those of the orbital fat body and supraorbital fossa are the smallest. In the other regions the cells have intermediate sizes. Statistical elaboration of the data has shown that: 1) in every site the range of variation in cell size is very high; 2) in the same individual the limits of the range of variation in cell size between the fat deposits in different sites are the wider, the higher the mean cell size; 3) the limits of the range of variation in fat cell sizes between corresponding regions in different individuals are closely correlated with the mean cell size. The suggestion is advanced that in the sites with very variable cell sizes, lipids are more readily mobilized; but such hypothesis requires further substantiation.