Objective To study the effect of caveolin-1 gene expression on the proliferation of human gastric adenocarcinoma cells,and to explore the possibility for its future usage in gene therapy.Methods The full-length caveolin-1 gene was stably transfected into the MGC803 cell line by lipofectin.The Pcl neo vector was transfected at the same time as mock control.The expression of caveolin-1 was detected by Western blot in both the caveolin-1 gene transfected MGC803 cells and the controls.The cell cycle was analyzed by flow cytometry.Results After transfected with caveolin-1,MGC803 cells significantly up-regulated the expression of caveolin 1 and extended their doubling time.The cell proliferation was inhibited and the cell cycle was arrested in the G_0/G_1 phase.Conclusion Caveolin-1 can inhibit the proliferation of MGC803 cells and induce cell cycle arrest in G_0/G_1 phase.

Objective To evaluate the effect of sodium nitroprusside(SNP)and N-nitro-l-arginine-mythel-ester (L-NAME) on apoptosis of spermatogenic cells in rats. Methods Fourty adult male Sprague-Dawley rats (60-70days) were divided into four groups.Each group was injected intraperitoneally with one of the following agents, once a day, for 12 days: 1. SNP; 2.L-NAME;3.SNL+L-NAME;4.Normal saline NS group.Two hours after the last time injection the rats were sacrificed.TUNEL staining and flow cytometry analysis were used to detect the apoptosis of spermatogenic cells. Results Sub-monoploid and apoptosis index (AI) in SNP group was significantly higher than that of NS group and sub-monoploid and apoptosis index (AI) in L-NAME group were significantly lower than that of NS group by FCM and TUNEL (P0.5) was found.Conclusion SNP can accelerate the apoptosis of spermatogenic cells and L-NAME can inhibite the apoptosis of spermatogenic cells,The effect of SNP and L-NAME on apoptosis of spermatogenic cells probably occurs through the action of nitric oxide.

OBJECTIVETo observe the effects of nitric oxide(NO) on the DNA ploidy of germ cells and to evaluate the role of NO in modulating spermatogenesis by using SNP, a donor of NO and N-nitro-l-arginine-mythel-ester(L-NAME), an inhibitor of nitric oxide synthese(NOS) in rats physically in vivo.

METHODSForty adult male, Sprague-Dawley rats (60-70 days) were divided into four groups, and injected ultraperitoneally with one of the following agents (once a day, for 12 days): SNP, L-NAME and SNP + L-NAME with normal saline. Two hours after the last injection the rats were sacrificed. The sera were collected and stored at -70 degrees C for subsequent hormone assay. The concentration of serum testosterone was measured by radioimmunoassay. Serum NOx- (nitrite/nitrate) concentration was measured by Greiss method. DNA of spermatogenic cells was detected by flow cytometry(FCM), and the percentage of 1c, 2c and 4c germ cells calculated.

RESULTSIn the SNP treatment group, the serum concentration of NOx- was higher, testosterone concentration was lower and the number of 1c cells was smaller compared with the control group. However, in rats treated with L-NAME, the concentration of NOx- was significantly lower, testosterone concentration was higher and the number of 1c cells was larger compared with the control group(P < 0.01). No changes were observed in the SNP + L-NAME group.

CONCLUSIONEnhancing ectogenous NO will suppress spermatogenesis while inhibiting NO productive pathway will promote it.

Animals ; DNA ; analysis ; Flow Cytometry ; Male ; NG-Nitroarginine Methyl Ester ; pharmacology ; Nitric Oxide ; physiology ; Nitroprusside ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Spermatogenesis ; drug effects