In situ binding and immunocytochemistry of insulin-like growth factor I receptors in primary cultures of porcine adipose tissue stromal vascular cells treated with indomethacin.
An autoradiographic technique for localizing [125I]IGF-I binding was adapted to primary cultures of pig stromal-vascular (S-V) cells to study the effects of pig serum (PS) and (or) indomethacin (Indo) on IGF-I and fibronectin (FN) receptors. Computer assisted image analysis revealed that the percentage of [125I]IGF-I binding decreased (P < .001) in cultures (7 d) treated with Indo compared with 2% PS alone. Binding of [125I]IGF-I analog (low-binding affinity for the IGF-I binding proteins) also decreased (P < .001) in 7-d cultures treated with Indo. The unlabeled IGF-I analog was more effective than unlabeled IGF-I at decreasing (P < .001) binding of [125I]IGF-I. Number of fat cell clusters and fat cell area (total lipid deposition) increased (P < .001) with PS + Indo compared with PS or Indo alone. Immunocytochemical staining (fluorescein isothiocyanate) of IGF-I receptors with a polyclonal antibody (flow cytometric analysis) decreased (P < .001) from 1 to d 3 and did not change from 3 to 7 d with PS alone. However, the percentage of reactive cells decreased (P < .05) when Indo was added to PS. In contrast, the number of cells detected with the FN receptor antibody increased fourfold (P < .01) from 1 to 7 d in cultures with PS alone and decreased (P < .05) when Indo was present. Undifferentiated cells around fat cell clusters were reactive for the IGF-I receptor, but fat cells showed no reactivity.(ABSTRACT TRUNCATED AT 250 WORDS)
Richardson
R L
RL
Agricultural Research Service, USDA, Athens, GA 30163.
Hausman
G J
GJ
Wright
J T
JT
D000273:Adipose Tissue / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001345:Autoradiography; D002478:Cells, Cultured; D005434:Flow Cytometry; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007213:Indomethacin / Q000494:pharmacology*; D050356:Lipid Metabolism; D008856:Microscopy, Fluorescence; D017526:Receptor, IGF Type 1 / Q000032:analysis / Q000378:metabolism*; D017469:Receptors, Fibronectin / Q000032:analysis / Q000378:metabolism; D017154:Stromal Cells / Q000187:drug effects / Q000378:metabolism*; D013552:Swine / Q000378:metabolism*
D017469:Receptors, Fibronectin; D017526:Receptor, IGF Type 1; D007213:Indomethacin