Effects of levcromakalim on pulmonary arterial endothelial cells and smooth muscle cells exposed to hypoxia / 中国病理生理杂志

ABSTRACT

AIM: To explore the effects of levcromakalim(Lev) on pulmonary arterial endothelial cells (PAEC) and smooth muscle cells (PASMC) exposed to hypoxia and the mechanisms involved. METHODS: The effects of Lev on i, and expression of PKC ?, eNOS, iNOS and PDGF-B mRNA and protein levels were observed. The nitrite (NO- 2) and entothelin-1(ET-1) concentrations in supernatant in cultured PAEC and PASMC were measured. The proliferation and apoptosis of PASMC was also detected. RESULTS: When PASMC were exposed to hypoxia, Lev reduced concentration of ET-1 in cultured cell supernatant, lowed the expression of PKC ?, iNOS and PDGF-B both at mRNA and protein levels, decreased i concentration, increased proliferation and promoted the apoptosis in PASMC. However, in the presence of Lev, the i concentration was not changed in the hypoxic PAEC. The NO- 2 concentration in cultured cell supernant and expression of eNOS at mRNA and protein levels in hypoxic PASMC and PAEC were also unchanged. The downregulated ET-1 activity in PASMC and PAEC and proliferation in PASMC involved in the inhibition of PKC ? signaling pathway. CONCLUSIONS: Lev reduce some disadvatage effect of hypoxia on PASMC and PAEC. The mechanism of Lev action may partly involve in the downregulation of PKC ? signaling functions.