Effects Of Androgen On Extracellular Vesicles From Endothelial Cells In Rat Penile Corpus Cavernosum

Background:The explicit mechanism of erectile dysfunction(ED)caused by low androgen status is unknown.It was reported that eNOS was expressed in extracellular vesicles(EVs).Androgen may regulate erectile function by affect the release of EVs from endothelial cells.Objective:To investigate whether androgen affects the production of EVs and nitric oxide(NO)in endothelial cells of rat penile corpus cavernosum.Materials and Methods:Endothelial cells of rat penile corpus cavernosum were isolated,purified and identify from 6-week-old healthy male Sprague Dawley rats.Endothelial cells were treated with different concentrations of dihydrotestosterone(DHT)in a cell culture medium,as follows:no-androgen group(NA group,DHT 0 nmol/L),very-low androgen group(VLA group,DHT 0.1 nmol/L),low androgen group(LA group,DHT 1nmol/L),and physiological concentrations androgen group(PA group,DHT 10nmol/L).After 24 hours,EVs of supernatant in each group were isolated and identified.The content of EVs and NO in the supernatant and the expression of CD9,CD63,TSG101,and eNOS in EVs were detected.Results:The endothelial cells isolated from the corpus cavernosum of rats showed a typical"paving stone"or"cobblestone-like"arrangement.The positive rate of CD31 was 94.48±2.56%and the rate of v WF positive cells was 94.70±2.94%.The EVs isolated from supernatant showed a typical"cup-like"or"dish-like"structure,the size of EVs was ranged from 110 to 140nm,and the positive expression of CD9,CD63,TSG101,and eNOS was found in EVs.The concentration of EVs was lower in the NA group(2.52±0.24×10~9Particles/mL)compared with other groups(VLA group:3.98±0.45×10~9Particles/mL,LA group:6.60±0.32×10~9 Particles/mL,PA group:7.92±0.28×10~9 Particles/mL)(P<0.01),it was lower in the VLA compared with LA(P<0.01),and it was lower in the LA compared with PA(P<0.01).The level of eNOS was lower in the NA group compared with other groups,it was lower in the VLA compared with LA(P<0.05),and it was lower in the LA compared with PA(P<0.01).The content of NO was lower in the NA group(11.80±1.65μmol/L)compared with other groups(VLA group:27.83±4.33μmol/L,LA group:51.43±5.06μmol/L,PA group:69.95±3.51μmol/L)(P<0.01),it was lower in the VLA compared with LA(P<0.01),and it was lower in the LA compared with PA(P<0.01).When the concentration of DHT in endothelial cell culture medium ranged from 0 to 10 nmol/L,the concentration of DHT was positively correlated with the content of EVs and NO.Conclusion:Decrease in eNOS-expressing EVs is one mechanism of NO reduction in endothelial cells of rat corpus cavernosum caused by low androgen levels.