Effect of Vitamin C on Primary Rat Adipocyte Apoptosis Induced by TNF-α

Abstract: Primary rat adipocyts were treated with 5， 10， 50， 100 mmol/L vitamin C (vit C) and combination of vit C (5-100 μmol/L) and 10 ng/ml TNF-α， respectively， to investigate their effect on adipocyte apoptosis. The apoptotic rate of adipocytes was measured by flow cytometry. The morphologic change of fat cells was observed with optical microscope and transmission electron microscope. The results show that both higher concentration of vit C (100 μmol/L) alone and its combination with TNF-α could significantly increase apoptosis rate of adipocytes (P<0.01) and the effect of combination with TNF-α was more apparent than TNF-α alone (P<0.01). No apoptosis was detected in adipocytes treated with lower dose of vit C (5-50 μmol/L) and the TNF-α-induced apoptosis was markedly inhibited by these concentrations of vit C. The feature of apoptosis was observed in adipocytes treated with 100 mmol/L vit C， i.e. cellular shrinkage and round， condensation of chromatin adjacent to nuclear membrane， nuclear fragmentation of apoptotic bodies which were rapidly engulfed by neighboring cells. The data suggest that high dose vit C (100 μmol/L) may cause adipocyte apoptosis and markedly enhance TNF-α-induced apoptosis.

CSTR: 32200.14.cjcb.2005.04.0024