[The disturbance of calcium homeostasis in vascular smooth muscle proliferation after balloon denudation].

OBJECTIVE

To investigate the changes of calcium homeostasis in smooth muscle cells (VSMC) and the role of disturbance of calcium homeostasis in VSMC proliferation after balloon denudation.

METHODS

Assay of the cellular incorporation of 3H-leucine and measurement of 45Ca transport were done on the model of balloon-denuded aorta in rat.

RESULTS

Endothelial injury induced VSMC proliferation, intimal thickening. After balloon denudation, VSMC calcium influx increased (3 days after balloon denudation, 3.28 +/- 0.14 vs 4.12 +/- 0.28, P < 0.05; 10 days 3.31 +/- 0.09 vs 4.09 +/- 0.21 nmol/10(6) cells, P < 0.01), and calcium efflux decreased, and calcium content increased (3 days after balloon denudation 695 +/- 33 vs 995 +/- 54, P < 0.01; 10 days 709 +/- 32 vs 1022 +/- 94 nmol/10(6) cell, P < 0.01). SR and mitochondria calcium uptake increased. Calcium antagonist, verapamil not only regulated the disturbance of calcium homeostasis, but also inhibited endothelium injury-induced VSMC proliferation.

CONCLUSION

The disturbance of calcium homeostasis is probably one of the underlying mechanisms of VSMC proliferation induced by balloon denudation.