Effects of protopine on proliferation of cultured rabbit aortic vascular smooth muscle cells

AIM To study the effect of protopine (Pro) on proliferation of cultured rabbit aortic vascular smooth muscle cells (VSMC) induced by endothelin 1(ET) or without ET. METHODS The method of celluar culture, the number of VSMC, [ 3H] TdR incorporation into DNA assay, MTT method and electronic microscopy were performed for the effect of Pro on proliferation of cultured rat vascular smooth muscle cell. RESULTS It was observed that exposure of VSMC to ET could markedly stimulate the proliferation of VSMC and increased respectively in MTT OD values and the DNA synthesis of VSMC. The concentration 1 μmol·L -1 ,10 μmol·L -1 , 100 μmol·L -1 of Pro significantly decreased the number of VSMC, the absorbance (A) of MTT and [ 3H] TdR incorporation induced by ET 1( P 0 01 or P 0 05). While the proliferation of normal VSMC was decreased only by the concentration 10 μmol·L -1 , 100 μmol·L -1 of Pro, and the inhibition rate is lower than ET groups. Furthermore, Pro could antagonize morphological changes of VSMC. CONCLUSION Pro has an effective inhibition on VSMC proliferation induced by ET 1 or without ET 1, and the inhibition rate increased by Pro concentration rising and time passing by. Furthermore, the inhibition of Pro to the proliferation of VSMC is more significantly induced by ET than treated without ET. This suggests that Pro could be of interest to prevent and cure arteriosclerosis clinically.