| Objective:To investigate whether low androgen status inhibits erectile function of rats through regulating the expression of P2 X receptors.Methods:Thirty-six 8-week-old male SD rats were randomly divided into six groups:sham-operated groups(4w-sham,8w-sham),castration groups(4w-cast,8w-cast)and androgen replacement after castration groups(4w-cast+T,8w-cast+T).The maximum intracellular pressure(ICPmax)/mean arterial pressure(MAP),the contents of serum testosterone and NO,and the expressions of P2X1,P2X2,P2X3,eNOS,p-enos,ROCK1 and ROCK2 in the cavernous penis of rats were determined.Results:there was no significant difference in the age and weight of six groups of SD rats.Serum T(5.16 ± 0.23 nmol / L,3.18 ± 0.25 nmol / L)and no content(6.77 ± 0.38? mol / gprot,3.12 ± 0.42 ? mol / gprot)of penile cavernous tissue were significantly lower in castrated 4-week group and castrated 8-week group than in sham operated 4-week group,sham operated 8-week group,castrated + testosterone replacement 4-week group,castrated + testosterone replacement 8-week group(18.02 ± 2.33 nmol / L,17.99 ± 2.12 nmol / L,17.86 ± 3.02 nmol / L)?18.01±2.97 nmol/L;12.06±0.79 ?mol/gprot?12.98±1.34 ?mol/gprot?12.89±0.62 ?mol/gprot?13.02±0.57 ?mol/gprot)(P<0.01)? The levels of serum T(3.18 ± 0.25 nmol / L)and no in penile cavernous tissue(3.12 ± 0.42 ? mol / gprot)were significantly lower in ovariectomized group than in ovariectomized group(5.16 ± 0.23 nmol / L,6.77 ± 0.38 ? mol / gprot)(P < 0.05).The icpmax / map of the castration 4-week group and the castration 8-week group were significantly lower than that of the sham operation 4-week group,the sham operation 8-week group,the castration + testosterone replacement 4-week group and the castration + testosterone replacement 8-week group(P < 0.01).The icpmax / map of the castration 8-week group was significantly lower than that of the castration 4-week group(P < 0.05).P2X1,P2X2 and P2X3 were mainly expressed in the intracellular membrane and cytoplasm of vascular smooth muscle cells and endothelial cells in penile corpus cavernosum of rats.The protein expression of P2X1.The protein expression of P2X1,P2X2 and P2X3 in castration 4-week group and castration 8-week group was significantly higher than that in sham operation 4-week group,sham operation 8-week group,castration + testosterone replacement 4-week group and castration + testosterone replacement 8-week group(P < 0.01).The expression of P2X1,P2X2 and P2X3 in the 8-week group was significantly higher than that in the 4-week group(P < 0.05).The results of Western blot showed that the expression of P2X1,P2X2,P2X3,Rock1 and Rock2 protein in the castration 4-week and 8-week groups were much higher than that in the sham operation 4-week group,sham operation 8-week group,castration + testosterone replacement 4-week group and castration + testosterone replacement 8-week group(P < 0.01).The expression of P2X1,P2X2,P2X3,Rock1 and Rock2 in the 8-week castration group was significantly higher than that in the 4-week castration group(P < 0.05);the expression of eNOS and p-enos in the 4-week castration group and 8-week castration group was significantly lower than that in the 4-week sham operation group,8-week sham operation group,4-week castration + testosterone replacement group and 8-week castration + testosterone replacement group(P < 0.01).The expression of eNOS and p-enos in the 8-week castration group was much lower than that in the 4-week castration group(P < 0.05).The expression of P2X1,P2X2 and P2X3 was negatively correlated with the serum T level of rats in each group.The correlation equations were: Y=-3.197+0.008 X,r=-0.822,P<0.01;Y=-2.887+0.007 X,r=-0.786,P<0.01;Y=-2.997+0.033 X,r=-0.674,P<0.01.Conclusion:Low androgen status may inhibit erectile function by up-regulating the expression of P2X1,P2X2,P2X3 and RhoA/Rho kinase,reducing the ratio of p-eNOS/eNOS and the content of NO in penile corpus cavernosum of rats. |
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