[The protective function and mechanism of notoginsenoside Rb1 against hypoxia hypercapnia-induced pulmonary vasoconstriction].

Objective: To explore the protective function and mechanism of notoginsenoside Rb1 against hypoxia hypercapnia-induced pulmonary vasoconstriction (HHPV).

Methods: The pulmonary artery smooth muscle cells of healthy male SD rats were primarily cultured and the second to the fifth subcultured cells were incubated with 8, 40, and 100 mg/L notoginsenoside Rb1 respectively under the hypoxia-hypercapnia condition (1% O2 and 6% CO2). The cells were harvested for 24 h. The phosphated extracellular signal-regulated kinase (p-ERK) protein expression of the cells was detected by Western blot. The mRNA expressions of ERK1 and ERK2 were detected using half quantitative reverse transcription polymerase chain reaction (RT-PCR).

Results: The expression of p-ERK protein, the mRNA expressions of ERK1 and ERK2 were weakly positive in the control group. Their expressions in the hypoxia-hypercapnia group were obviously enhanced (P < 0.01). After intervention of Rb1 at different concentrations, their expressions were obviously lowered (P < 0.05, P < 0.01) in a dose-dependent manner. The optimal effects were obtained at the dose of 100 mg/L. The expression of p-ERK protein was significantly positively correlated with mRNA expressions of ERK1 and ERK2 in notoginsenoside Rbl-treated groups (r = 0.500, P < 0.01; r = 0.977, P < 0.01).

Conclusions: ERK1/2 pathway might play a role in the rat HHPV. Notoginsenoside Rb, could alleviate HHPV by inhibiting the ERK1/2 pathway.