Metallothionein inhibits rat vascular fibroblasts activation induced by homocysteine

AIM: To study the effects of exogenous metallothionein (MT) and ZnCl 2-induced MT production on biological action of homocysteine(HCY)in vascular fibroblasts METHODS: -TdR, -Pro incorporation and LDH leakage were measured, the cellular viabilities were calculated by trypan blue exclusion test and the intracellular contents of MT were assayed by [ 109 Cd]-hemoglobin saturation method in cultured rat vascular fibroblasts. RESULTS: Proliferation, collagen production of vascular fibroblasts in HCY-treated group were significantly increased compared with control group in a concentration-depedant manner. HCY (500 μmol/L) increased LDH leakage and decreased the cellular viabilities ( P 0 05 or P 0 01). -TdR incorporation,-Pro incorporation, collagen secretion and LDH leakage were all decreased in MT (1×10 -5 mol/L, 1×10 -4 mol/L) plus HCY(500 μmol/L) incubated group, compared with HCY alone group, respectively ( P 0 05 or P 0 01). MT content in ZnCl 2 pretreatment group was increased compared with control group. Proliferation,collagen production and LDH leakage in HCY group pretreated with ZnCl 2 were decreased whereas the cellular viabilities were increased compared with HCY alone group. CONCLUSIONS: The results shows that HCY induces proliferation and collagen production of vascular fibroblasts. Both exogenous MT and endogenous MT induced by ZnCl 2 inhibite the above-mentioned effects of HCY on vascular fibroblasts. MT inhibites vascular fibroblast activation induced by HCY, which may be related to its vascular protection.