Role of non-MLC20 pathway on PDGF regulation of vascular reactivity during shock and its relation with Caldesmon and HSP27

ZHU Yu; PENG Xiao-yong; LAN Dan; LI Tao

Abstract：Objective To explore the mechanism of non-MLC20 phosphorylation dependent pathway on PDGF regulation of vascular reactivity following shock and its relation with Caldesmon and HSP 27.Methods For-ty-eight SD rats with a weight of 200-250 g were selected.The superior mesenteric arteries(SMAs)of the rats were analyzed .The vascular reactivity and the change of MLC 20 phosphorylation after hypoxemia and the effect on the activity of HSP27 and Caldesmon were observed .After the inhibition of Caldesmons and HSP 27 by antisense oli-godeoxynucleotide ( AODN) ,the regulation of PDGF on vascular reactivity and the change of MLC 20 phosphorylation were also observed . Results Vascular reactivity decreased significantly after shock . Different concentration of PDGF(40ng/ml,60ng/ml,80ng/ml,100ng/ml) increased the vascular reactivity after shock and showed obvious dose-dependent manner .Effects of PDGF at different concentration on MLC 20 phosphorylation did not increase with the increase of dosage .Different concentration of PDGF regulated Caldesmon and HSP 27 phosphorylation and in-creased with the increase of dosage .The AODN of Caldesmon and HSP27 could inhibit the increase of vascular re-activity induced by PDGF but could not inhibit the increase of MLC 20 phosphorylation induced by PDGF .Conclu-sion Non-MLC20 phosphorylation pathway takes part in the regulation of vascular reactivity after shock .Its mech-anism is related with Caldesmon and HSP 27.