ABSTRACT
This study investigated the protective effect of EGB761 on blood vessels of denervated gastrocnemius of rat and its possible mechanism.Fifteen male adult SD rats were randomly divided into three groups:normal control group (n=3),control group (n=6) and EGB761-treated group (n=6).The rats in the control and EGB761-treated group underwent a neurotomy to bilateral sciatic nerves.Then,they were administered EGB761 [100 mg/(kg·d)] and isovolumic normal saline,respectively by gavage everyday.No treatment was given to the rats in the normal control group.Gastrocnemius was harvested at 1 and 3 week(s) postoperatively in each group.Immunohistochemical method was used to detect the ratio of capillary/fiber (CFR) of denervated gastrocnemius and the expression of VEGF,fetal liver kinase -l(Flk-1) receptor and HSP70 in the vascular wall.The results showed that in the normal control group,VEGF,Flk-1 and HSP70 were expressed in the vessel wall of gastrocnemius,with Flk-1 expressed only in the endothelial cell of vessels.CFR in the EGB761-treated group was significantly higher than that in the control group at 1 week and 3 week(s) after neurotomy.The expression of VEGF and Flk-1 in the vessel wall of both control and EGB761-treated group was much lower than that in the normal control group,and the expression of these proteins in the EGB761-treated group was decreased as compared with that in the control group.The expression of HSP70 in the vessel wall of both control and EGB761-treated groups was enhanced when compared with that in the normal control group,and it was substantially augmented in the EGB761-treated group in comparison to the control group.It was concluded that EGB761 has a protective effect on blood vessels of denervated gastrocnemius,which is related to the increased HSP70 expression but not the expression of VEGF and its receptor Flk-1.
ABSTRACT
Adult stem cells from skeletal muscle cells were induced to differentiate into cardiocytes to see if stem cells from another different but histologically-comparable tissues can differentiate to the target cells. Skeletal muscles-derived stem cells (MDSCs) were isolated from adult skeleton muscle tissues by differential adhesion,and immunocytochemically identified by using Sca-1. In order to induce the proliferation but not differentiation of MDSCs,the cells were cultured in Dulbecco's modified Eagle's medium/F12 (DMEM/F12) supplemented with 1:50 B27,20 ng/mL basic fibroblast growth factor (bFGF),20 ng/mL epidermal growth factor (EGF) in a suspension for 6 days. Then these stem cells were treated with 5 μmol/L 5-azacytidine for 24 h in an adherence culture. The characteristics of induced cells were examined by immunocytochemistry,quantitative real time RT-PCR and morphological observation of cell phenotype. Our results showed that the appearance of some cells gradually changed from spindle-shape into polygonal or short-column-shape. Some of these post-treated cells could contract spontaneously and rhythmically. The expression of GATA-4 and cTnT was increased 1 and 2 week(s) after the treatment. And about 16.6% of post-treated cells were cTnT-positive. Therefore,we are led to conclude that skeletal muscle-derived stem cells could differentiate into cardiocyte-like cells,which exhibited some characteristics of cardiocytes.