Ligustrazine in the prevention of chronic hypoxic pulmonary hypertension in rat and its relationship to the gene expression of nitric oxide synthase / 中国药理学通报

ABSTRACT

A model of chronic hypoxic pulmonary hypertension (HPH) was reconstructed in rats exposed to hypoxia with normal pressure for 14 d. Chronic HPH was prevented by giving Ligustrazine (LTZ) in an intraperitoneal dose of 80 mg ?kg-1 wt. twice daily. The mean pulmonary arterial pressure (mPAP), plasma and pulmonary small arterial cGMP level, and mRNA expression of nitric oxide synthase (NOS) gene in lung tissues were studied. The results showed that the mPAP was significantly higher, but plasma and pulmonary small arterial cGMP level as well as mRNA expression of NOS gene in lung tissues were markedly lower in chronic hypoxic rats than those in control animals. LTZcould reverse those changes of above indexes in hypoxic rats, but did not affect those indexes in normal rats. There was a strong negative correlation between cGMP level and mPAP. It is suggested that the lower mRNA expression of NOS gene in hypoxic rats may be one of pathogenetic mechanisms in chronic HPH, and LTZ can increase the mRNA exprssion of NOS gene and the production of nitric oxide in hypoxic rats, which may be an important mechanism in LTZ preventing chronic HPH.