Dimethylsulfoxide-soluble Smoking Particles and Nicotine Affect Vascular Contractibility

The aim is to study the effect of dimethylsulfoxide-soluble smoking particles (DSP) and nicotine on the contractility of rat mesenteric artery. The superior mesenteric artery segments were cultured with DSP or nicotine for 24 h. The vascular contractibility was recorded with myograph system. DSP 0.4 mL/L and nicotine 0.48 and 0.96 mg/L shifted the concentration-contractile curves induced by sarafotoxin 6c, a selective agonist for ETB receptor toward the left with increased E-max. DSP 0.4 mL/L and nicotine 0.96 mg/L shifted ETA receptor-mediated the concentration-contractile curves toward the left with increased E-max. However, nicotine 0.06 mg/L which is the equivalent concentration of nicotine in DSP 0.4 mL/L did not affect the curves and the E-max mediated with ETA receptor and ETB receptor. DSP 0.2 and 0.4 mL/L shifted the concentration-contractile curves induced by noradrenaline toward the right with decreased E-max. Neither did nicotine 0.06 and 0.96 mg/L. Both DSP and nicotine shifted the concentration-contractile curves induced by 5-hydroxytryptamine (5-HT) toward the right parallely. DSP changed the phenotypes towards an increased efficacy of ETA receptor and ETB receptor, and a reduced efficacy of 5-HT receptor and alpha-adrenocceptor. The effects of DSP on ETB receptor, ETA receptor and alpha-adrenocceptor were independent of nicotine. The effect on 5-HT receptor was responsible to nicotine.