Effects Of Constant Magnetic Fields On The Proliferation Of Human Umbilical Arterial Vascular Smooth Muscle Cells And Intracellular Free Calcium

Research Background and AimThe proliferation of vascular smooth muscle cells (VSMC) is the main pathological characteristics of restenosis (RS) after percutaneous transluminal coronary angioplasty (PICA). Inhibition of VSMC proliferation is the vital therapeutic strategy of RS. At present, the medicine is the main method to prevent RS, but the result is not very well. The physical method becomes more and more attracting.. The experiment has already proved that the inhibiting effect of constant magnetic field (CMF) on aortic smooth muscle cells proliferation in rabbits. The report about the the effect of CMF on VSMC in human is not existing. The other experiments have proved that the cyclin has been activated and increased in the process of RS. Inhibition cell cycle may block up the proliferation of VSMC tunica ultima after blood vessel injury. It is an another important direction for prevention of RS by holding back cell cycle of VSMC.The experiment have studied the effects of constant magnetic fields of different intensity on the proliferation of human umbilical arterial vascular smooth muscle cells, as well as proliferation models of cultured human umbilical arterial VSMC induced by Ang II, After being exposed to the CMFs, the amountof VSMC proliferation were determinde, and flow cytometry were used to analyze cell cycle, discussing if the CMFs have an influence on the proliferation ofVSMC.The report said that the CMFs affect the velocity of shift and arrangement pattern on ion, such as potassium, calcium and so on. It leads to the change of proliferation of VSMC. The experiment have studied that the effects of constant magnetic fields on the intracellular free calcium of human umbilical arterial vascular smooth muscle cells to discuss the mechanism of CMF affecting the proliferation of VSMC. MethodsThe human umbilical arterial vascular smooth muscle cells (VSMC) were cultured in vitro. The experimental models of proliferation of cultured human umbilical arterial VSMC and VSMC induced by Angllwere also established, and the CMF with various intensity was imposed to the VSMC. MTT and 3H-TdR incorporation method (A-value and cpm-value) were used to determine the amount of VSMC proliferation, and flow cytometry to analyze cell cycle. The intracellular free calcium concentration of human umbilical arterial vascular smooth muscle cells were detected by laser scanning confocal microsopy. Data in the results was statistically analyzed with SPLM software. Results1. The amount of VSMC proliferation was significantly lower than those of the control group under the CMF 0.5, 1, 2 and 5mT, contrast with the amount of VSMC proliferation was significantly higher than those of the control group under the CMF 10, 30 and 60mT. It is dominant in an intensity-dependent nonlinear manner.2. The CMF of 1 and 5mT could decrease the amount of VSMC proliferation by Angll, and hold-back VSMC from static phase (Go/Gi) to DNA synthetic(S) and mitotic phase (G2/M). The study demonstrated that CMF of 1 and 5mT can significantly inhibit the human VSMC proliferation .3. The CMF affected the intracellular free calcium concentration of human umbilical arterial vascular smooth muscle cells. The CMF(5mT) caused a persistent decreasing of intracellular free calcium concentration of VSMC fromlOmin to 50min. Conclusion1. The CMF with suitable-intensity could significantly inhibit proliferation of VSMC.2. The CMF could decrease the amount of VSMC proliferation induced by Ang II, and hold back VSMC from static phase to DNA synthetic and mitotic phase.3. The CMF could inhibit proliferation of VSMC by decreasing the intracellular free calcium concentration of VSMC.4. The CMF could markedly inhibit proliferation of VSMC, which might be useful in treatment of RS after PTC A.