Increased expression of 5-hydroxytryptamine transporter gene in monocrotaline-induced pulmonary hypertension in rats / 中国药理学通报

ABSTRACT

Aim To study the relationship between pul-monary hypertension (PHT) and 5-hydroxytrapta-mine transporter (5-HTT) in the pulmonary arteries (PAs) from normal and monocrotaline (MCT) induced pulmonary hypertension rats. Methods MCT-treated rats were used as a model for chronic PHT.Concentration-response curves of 5-hydroxytraptamine induced pulmonary vasoconstriction were established. The medial wall thickness of pulmonary arteries was measured. Semi-quantitative RT-PCR was performed to identify the expression of 5-HTT mRNA in rat PAs.Results 5-HT induced vasoconstriction response of PAs from MCT rats was significantly increased.The thickness of pulmonary vascular medial walls was increased in MCT rats. A significantly higher level of 5-HTT mRNA expression was detected in PAs from MCT rats. The ratio of the PCR products of 5-HTT gene to those of ?-actin gene was higher in MCT rats than in control rats. 5-HTT mRNA expression of pulmonary arteries correlated with the thickness of pulmonary vascular medial walls in rats.Conclusions MCT-induced pulmonary vascular remodeling and increased vascular contractile response to 5-HT were accompanied with enhanced level of 5-HTT mRNA expression and there existed correlation between the wall thickness of pulmonary arteries and 5-HTT mRNA expression,indicating 5-HTT is an important mechanism involved in pulmonary hypertension.