Effects Of Glycosaminoglycan From Scallop Skirt On The Proliferation Of Vascular Smooth Muscle Cells Induced By Basic Fibroblast Growth Factor

Objective To investigate the inhibitory effects of scallop skirt glycosaminoglycan (SS-GAG) on the proliferation of vascular smooth muscle cells (VSMC) cultured in vitro,and to discuss its mechanisms of anti-atherosclerosis .Methods 1. The vascular smooth muscle cells had been cultured in vitro , and induced by basic Fibroblast Growth Factor (bFGF) , then the proliferatory model had been established . MTT chromatometry was used to study the effects of SS-GAG on the VSMC proliferatory activity . 2. In vitro it took a model of VSMC proliferation induced by bFGF , many methods including xanthine oxidase method and TBARs were used to test the activities of superoxide dismutase (SOD) and the levels of malanyldiadeyhde (MDA). 3. In vitro it took a model of VSMC proliferation induced by bFGF , some chemical methods were used to analyze the activities of glutathione peroxidase (GSH-PX) and the levels of the total anti-oxidation capacity (T-AOC) . 4. In vitro it took a model of VSMC proliferation induced by bFGF , some chemical methods including nitrate reductase method were used to observe the total activities of nitric oxide synthase (NOS) and the secretion of nitric oxide (NO) . 5.With the help of electron microscope , the changes of the ultrastructure of VSMC proliferation induced by bFGF had been observed after the incubation of SS-GAG . 6.By means of flow cytometry (FCM) , we observed the effects of SS-GAG on the VSMC proliferation dynamics .7.In situ hybridization assay was used to observe the effects of SS-GAG on the mRNA expressions of the A chain of PDGF within proliferatory vascular smooth muscle cells.Results 1. Compared with model group, the VSMC proliferatory activities induced by bFGF can be lessened by SS-GAG (terminal concentration were 50ug/ml 100ug/ml and 200u/ml) (P<0.05, p<0.01). 2. Compared with model group, the MDA levels of VSMCproliferation induced by bFGF can be decreased by SS-GAG (terminal concentration were 50ug/mk 100ug/ml and 200ug/ml) (P<0.05, P<0.01); and there was no changes of the activities of SOD. The GSH-PX activities and the T-AOC of VSMC proliferation induced by bFGF can be increased by SS-GAG (terminal concentration were 100ug/ml and 200ug/ml) (P<0.05) . 3. Compared with model group, the activities of cellular NOS and the secretion of NO were higher (P<0.05, P<0.01) after the incubation of SS-GAG (terminal concentration were 100ug/ml and 200ug/ml) . 4. Under the electron microscope, SS-GAG (terminal concentration was 100ug/ml) can greatly inhibit the conversion of contractile type to synthetic type of VSMC . 5. Compared with model group , SS-GAG (terminal concentration were 50ug/mh 100ug/ml and 200ug/ml) can make the number of VSMC in S period of cell cycle increasing (P<0.01) . 6.Compared with model group, the expressions of the gene for the PDGF-A chain within the proliferatory VSMC induced by bFGF can be reduced by SS-GAG (terminal concentration were 100ug/ml and 200ug/ml) (P<0.05, P<0.01).Conclusion SS-GAG can lessen the proliferatory activities of VSMC induced by bFGF ,decrease the levels of MDA , promote the activities of GSH-PX and T-AOC ; and increase the excretion of NO , enhance the activities of NOS. These studies indicate that the anti-atherosclerosis effects may be related to the decreasing of the production of MDA ,. the enhancing of the activities of anti-oxidative system , the increasing of the activities of cellular NOS and the secretion of NO . SS-GAG can inhibit the proliferation of VSMC by inhibiting the conversion of contractile type to synthetic type of VSMC , decreasing the DNA syntheses in S period of cell cycle and reducing the transcription of the gene for PDGF-A chain so as to achieve the effects of anti-atherosclerosis .Postgraduate Chu Xiang-Hua (Pharmacology) Directed by Prof. Liu Sai...