Cytochemical and immunohistochemical evidence of direct origin of white adipocytes from mesenchymal cells.
OBJECTIVE
By using histochemical, enzymohistochemical and immunohistochemical methods the present study aims to find out specific morphological markers in the precursors of the white subcutaneous adipocytes of human and rat embryos, which could be used for identification and help in clarification of the origin of that cell type.


METHODS
On cryostat sections of subcutaneous tissue from the thigh region of human embryos and hind limb of rat embryos histological hematoxylineosin staining, Sudan III-hematoxylin staining and enzyme-histochemical reactions for lipoprotein lipase are performed. On paraffin section of the same material immunohistochemical reaction for leptin is performed.


RESULTS
The analysis reveals that the earliest preadipocytes possess specific histochemical, enzymohistochemical and immunohistochemical features, which characterize exclusively these cells but not the fibroblasts and endothelial cells scattered around in the subcutaneous tissue. These features include lipid drops, positive enzymohistochemical reaction for lipoprotein lipase and immunohistochemical expression for leptin.


CONCLUSIONS
The results could be used as evidence of direct origin of the white adipocytes from the embryonal mesenchyme through their own progenitor cells rather than through fibroblasts or endothelial cells.
Atanassova
Pepa K
PK
Department of Anatomy, Histology and Embryology, Medical University, Plovdiv, Bulgaria.
D017667:Adipocytes / Q000737:chemistry / Q000166:cytology* / Q000201:enzymology; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D019070:Cell Lineage / Q000502:physiology*; D005314:Embryonic and Fetal Development; D006801:Humans; D007150:Immunohistochemistry; D020738:Leptin / Q000032:analysis / Q000378:metabolism; D008071:Lipoprotein Lipase / Q000032:analysis / Q000378:metabolism; D008648:Mesoderm / Q000737:chemistry / Q000166:cytology* / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar; D040521:Subcutaneous Tissue / Q000737:chemistry / Q000196:embryology / Q000201:enzymology
D015415:Biomarkers; D020738:Leptin; D008071:Lipoprotein Lipase