Stimulating proliferation of aorta smooth muscle cells of rat by rat urotensin Ⅱ / 中国药理学通报

ABSTRACT

AIM　To investigate effect of urotensin Ⅱ (UⅡ)on proliferation of aort a smooth muscle cells （ASMC）of rat and study the signal transduction pathway o f it. METHODS　In cultured ASMC of rat, UⅡ was used to stimulate proliferation of these cells and levels of ［3H］-TdR incorporation were used to evaluate the speed of DNA synthesis, and different inhibitors were used to s tudy the action of different signal transduction pathway of mitogenic effect of UⅡ on VSMC. RESULTS　1×10-9～1×10-7 mol*L- 1 UⅡ caused marked concentration-dependent increasing of ［3H］-TdR i ncor poration of ASMC. ［3H］-TdR incorporation of 1×10-9,1×10-8 and 1×10-7 mol*L-1 UⅡ were 22%（P<0.05）, 57%（P<0.01）and 65%（P<0.01）higher than control. Nicardipine, H7, W7 and PD98059 , which are inhibitors of calcium channel, PKC, CaM-PK and MAPK respectively, inhibited the effects of UⅡ obviously, with the inhibitory rate by 55%（P< 0.01）, 27%（P<0.01）,18%（P<0.05）and 16%（P<0.05）respectively . CONCLUSION　UⅡ is a strong mitogen for VSMC and the mitogenic e ffect of UⅡ is probably mediated by Ca2+, PKC, CaM-PK and MAPK signal tr ansduction pathway.