[Effect of PDGF-AA on [Ca2+]i in vascular smooth muscle cells in SHRs]

To explore the relationship between proliferation and hypertrophy of vascular smooth muscle cells and PDGF-AA and PDGFR-alpha expression in SHRs and the role of [Ca2+]i in it.

Express difference of PDGF-AA, PDGFR-alpha, PDGFR-beta in SHR/WKY-VSMC was observed by Western blot. The effect of Ca2+ inhibitor (nimodipine) on proliferation, hypertrophy and free Ca2+ concentration of SHR-VSMC induced by PDGF-AA was observed by Western blot, [3H] incorporation and fluorescent digital image technique.

PDGF-AA and PDGFR-alpha expression was markedly increased in SHR-VSMC than in WKY-VSMC, but PDGFR-beta was not different in SHR and WKY-VSMC. PDGF-AA-stimulated PCNA expression, [3H] incorporation and [Ca2+]i increasing were observed in SHR-VSMC. Dose-dependent nimodipine-inhibited PCNA expression, [3H] incorporation and [Ca2+]i increasing induced by PDGF-AA also were observed in SHR-VSMC.

Spontaneously expression increasing of PDGF-AA and PDGFR-alpha in spontaneously hypertension rats (SHRs) may be one of the important factors on vascular reactivity and vascular modeling mediated through proliferation and hypertrophy in SHR-VSMC, and [Ca2+]i play an important role in this process.