Study of MAPK on effect of insulin on proliferation of vascular smooth muscle in SHR rats

Objective To study the effects and mechanism of insulin on proliferation and phenotypic transition of vascular smooth muscle cells(VSMCs) in spontaneously hypertensive rat(SHR).Methods VSMCs were enzymatically isolated from SHR and pretreated with insulin and/or PD98059.Their growth characteristics were evaluated by -thymidine incorporation;a-SM actin by immunocytochemical staining;MAPK by western-blot.Proliferation and migrationg of VSMCs were also observed.Results -thymidine incorporation in VSMCs from insulin group(10.38±0.82) was higher than that in VSMCs from PD98059 group(6.34±0.51,P0.05).Migration rate and proliferation rate of VSMCs from insulin group were about 4.04 times higher than VSMCs from PD98059 group(P0.05).Immunocytochemical staining of VSMCs revealed that α-SM actin in insulin group was weaker than in PD98059 group.Conclusion The study demonstrates a positive effects of insulin on proliferation and phenotypic transition in VSMCs of SHR,and MAPK may be involved in these.