title: An ultrastructural study of adipocyte precursors from epididymal fat pads of adult rats in culture.
abstract: It has been demonstrated that cells with poor or no lipid content, isolated from epididymal fat pads of young rats, develop fully into mature adipocytes in vitro. The ultrastructural feature of these cells during such a development have been studied recently. In the present work the electron microscopic aspects of similarly obtained cells from adult rats have been investigated. It has been found that no morphological differences are present in the cells immediately after isolation between young and adult rats. During culture the cells from both adult and young rats show the same maturative process, but in adult rats this process is generally slower and not homogeneous, suggesting the presence of two populations of adipocyte precursors. The former accumulate lipids quickly and have electron microscopic features very similar to those observed for young rat precursors, however maturation is still faster in the latter cells. The latter have electron microscopic aspects of less differentiated cells (some fibroblast-like features) during the first days of culture; however they show a similar development when longer culture periods are studied. These data suggest that the fibroblast-like cells seen after a period of time in culture probably represent an early stage of adipocyte precursor differentiation. Thus it is suggested that in adult mammals, there may be a population of adipocyte precursors present within the adipose tissue which upon stimulation by as yet unknown factors would develop fully into adipocytes.
mesh_terms: D000273:Adipose Tissue / Q000502:physiology / Q000648:ultrastructure*; D000375:Aging; D000818:Animals; D002469:Cell Separation; D002470:Cell Survival; D002478:Cells, Cultured; D002498:Centrifugation; D004822:Epididymis / Q000648:ultrastructure*; D008297:Male; D003012:Microbial Collagenase; D008854:Microscopy, Electron; D051381:Rats; D011919:Rats, Inbred Strains; D013234:Stem Cells / Q000502:physiology / Q000648:ultrastructure*; D014617:Vacuoles / Q000648:ultrastructure
chemical_list: D003012:Microbial Collagenase