| Objective:The purpose of this study was to explore whether low androgen through regulate A2A?A2BB Adenosine Receptor's expression affecting erectile.Methods:After adaptive feeding for one week,thirty-six male Sprague-Dawley rats were randomly divided into six groups:4w-cast+T group,4w-cast group,4w-sham group,8w-cast+T group,8w-cast group and8w-sham group?6 rats/group?.The groups of 4w-cast+T,4w-cast,8w-cast+T and8w-cast were performed surgery castration.After castration,Rats in the groups of 4w-cast+T and 8w-cast+T were subcutaneously injected with testosterone propionate at 3mg/kg qod,The rats of other groups were subcutaneously injected with corresponding dose of vegetable oil.After 4 weeks and 8 weeks,all groups of rats'body weight,testosterone,maximum intracavernous pressure,(ICPmax)and mean arterial pressure?MAP?were detected.The immunohistochemical examination and western blot were used to detect the expression of A2A,A2B,AKT and eNOS.The cAMP and cGMP levels in the corpus cavernosum of rats were assessed by ELISA.Results:The body weight?4w-sham:313.5±6.4g;4w-cast:313.7±8.5g;4w-cast+T:310.54±2.3g;8w-sham:312.6±7.8g;8w-cast:311.2±4.7g;8w-cast+T:316.6±3.8g?and MAP?4w-sham:106.98±3.98mmHg;4w-cast:104.51±1.82mmHg;4w-cast+T:105.43±4.70mmHg;8w-sham:104.63±2.63mmHg;8w-cast:106.67±4.58mmHg;8w-cast+T:107.80±4.53mmHg?have no significant difference.Serum T levels:4w-cast group?1.67±0.38?compared with 4w-sham group?21.45±1.87?and 4w-cast+T group?21.46±1.89?decreased significantly?P<0.01?,8w-cast group?0.37±0.06?compared with 8w-sham group?21.69±1.27?and 8w-cast+T group?20.34±2.23?decreased significantly?P<0.01?,and 8w-cast group compared with 4w-cast group decreased significantly?P<0.05?,4w-cast+T group,4w-sham group,8w-cast+T group,8w-sham group have no significant difference.3V/5V voltage stimulation ICPmax/MAP:4w-cast group?0.40±0.02?0.53±0.03?compared with 4w-sham group?0.68±0.03?0.79±0.03?and 4w-cast+T group?0.68±0.02?0.79±0.02?decreased significantly?P<0.01?,8w-cast group?0.29±0.02?0.39±0.01?compared with 8w-sham group?0.67±0.03?0.80±0.04?and 8w-cast+T group?0.69±0.04?0.81±0.02?decreased significantly?P<0.01?,and 8w-cast group compared with 4w-cast group decreased significantly?P<0.05?,4w-cast+T group,4w-sham group,8w-cast+T group and8w-sham group have no significant difference.The expression of A2AA and A2BB adenosine receptor in penile tissue of each group by immunohistochemical stains:The integrated optical density value?IOD?of A2AA have no significant difference in different groups?4w-sham group:634.12±126.02;4w-cast group:586.19±100.73;4w-cast+T group:606.27±89.53;8w-sham group:628.29±72.75;8w-cast group:601.55±82.53;8w-cast+T group:629.19±128.51?.The castration groups?4w-cast:703.35±78.39;8w-cast:477.64±70.12?compared with Testosterone replacement groups?4w-cast+T:1141.25±136.64;8w-cast+T:1184.16±150.41?and sham groups?4w-sham:1081.47±122.08;8w-sham:1094.68±97.04?,the IOD of A2B decreased significantly,and8w-cast group compared with 4w-cast group decreased significantly.The expression of the protein of A2A,A2B,AKT?eNOS in different groups of rats:The expression of the protein of A2AA have no significant difference in different groups?4w-cast group:0.220±0.024;4w-sham group:0.233±0.035;4w-cast+T group:0.218±0.033;8w-cast group:0.226±0.030;8w-sham group:0.228±0.036;8w-cast+T group:0.219±0.033?.The castration groups?4w-cast:0.076±0.008,0.104±0.008,0.235±0.012;8w-cast:0.023±0.004,0.053±0.046,0.185±0.009?compared with Testosterone replacement groups?4w-cast+T:0.320±0.038,0.500±0.035,0.541±0.025;8w-cast+T:0.317±0.028,0.491±0.029,0.533±0.032?and sham groups?4w-sham:0.324±0.042,0.492±0.011,0.544±0.027;8w-sham:0.310±0.029,0.495±0.030,0.532±0.023?,the expression of the protein of A2B,AKT and eNOS in the corpus cavernosum of rats decreased significantly,and 8w-cast group compared with 4w-cast group decreased significantly.cAMP and cGMP levels dected by ELISA:The castration groups?4w-cast:6.45±0.40,3.53±0.09pmol/mg protein;8w-cast:5.03±0.19,2.57±0.08pmol/mg protein?compared with Testosterone replacement groups?4w-cast+T:12.22±1.11,6.42±0.20pmol/mg protein;8w-cast+T:11.95±0.21,6.59±0.15pmol/mg protein?and sham groups?4w-sham:12.17±0.38,6.59±0.24pmol/mg protein;8w-sham:11.68±0.62,6.35±0.11pmol/mg protein?,the concentration of cAMP and cGMP in the corpus cavernosum of rats decreased significantly?P<0.01?,and 8w-cast group compared with 4w-cast group decreased significantly?P<0.05?,4w-cast+T group,4w-sham group,8w-cast+T group and 8w-sham group have no significant difference.Conclusion:Low androgen status has no effect on the expression of A2AA receptor in penile tissue of rats.However,it can inhibit the AKT/eNOS/cGMP signaling pathways and the production of cAMP in the corpus cavernosum of castrated rats by downregulating the expression of A2BB receptor,resulting in decreased of ICPmax/MAP. |
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