摘要
Objective: To investigate the effect of LPS on the proliferation and viability of rat vascular smoothmuscle cell in vitro. Methods: In cultured vascular smooth muscle cells(VSMCs) of SD rat, it was found that 1× 10 -1~1 × 10-5 g/ml LPS markedly stimulated the proliferation and DNA synthesis of VSMC in a dose--dependentmanner (P CO. 05). 5 × 10- 4-- 10 -3 g/ml LPS markedly inhibited the proliferation, DNA synthesis and viabilityof VSMC in a time--dependent manner (P <0. 01). N (--Nitro--L--Arginine (L--NNA )which could decrease theproduction of NO by inhibiting nitric oxide synthase (NOS) and antagonize the inhibitory effect of LPS. Thecontents of NO3, NO2 in medium were markedly increased in LPS group (P <0. 01), 48 h group vs 24 h groupincreased by 9. 1%, 72 h group vs 48 h group increased by 4. 5%. In high dose LPS group, positiveimmunohistochemical staining for inducible nitric oxide synthase was observed. Results:It was demonstrated thatlow dose LPS stimulated the proliferation and DNA synthesis of VSMC, while LPS at high dose markedly inhibitedthe proliferation, DNA synthesis and viability of VSMC. Conclusion: The inhibition of VSMC proliferationinduced by LPS is probably due to the increased release of NO by VSMC.
