ANATOMY AND CHEMICAL-COMPOSITION OF ADIPOSE-TISSUE IN WILD WOLVERINES(GULO-GULO) IN NORTHERN CANADA

Adipose tissue was dissected completely from 25 adult male and five ad ult female wolverines shot between October and March, 1990-1992 in Nor thwest Territories, Canada. The gross mass, mean adipocyte volume, lip id, protein and collagen contents were measured in adipose tissue from 13 superficial and internal depots homologous to those of other terre strial mammals. The total adipocyte complement was calculated from the mass of each depot and its site-specific adipocyte volume. Almost all the adipose depots found in other terrestrial mammals were present in wolverines and site-specific differences in adipocyte volume were sim ilar to those of other species. No significant sex differences were de tected. All depots except the cardiac adipose tissue enlarged with inc reasing fatness, but the superficial depots expanded faster than any o f the internal depots and the posterior superficial depots enlarged sl ightly faster than the anterior depots. The partitioning of adipose ti ssue between superficial and intra-abdominal depots, and between anter ior and posterior superficial depots, changed with fatness and was con sistent with predictions from allometric equations derived from data f rom other Carnivora. The total adipocyte complement was variable, with more than 70% of the specimens having 2-5 times as many adipocytes as predicted from allometric equations relating adipocyte complement to body mass in other carnivorous mammals. Consequently, the correlation between mean adipocyte volume and total dissectible adipose tissue was weak. Measurements of adipocyte volume from biopsies of adipose tissu e, and indices based upon the mass of thickness of one or a few depots , would therefore not provide an accurate estimate of fatness. The con centration of collagen was higher in the superficial and intra-abdomin al adipose depots of specimens collected in mid-winter than in homolog ous tissues of those killed in early winter, but there were no compara ble seasonal changes in the abundance of lipid or non-collagen protein .