Hypoandrogenism and the mode of cell death in the penile cavernosum tissue of male rats

ZHAO Xin; LI Jing; JIANG Rui

doi:10.13263/j.cnki.nja.2025.04.001

Abstract：Objective To study the mode of cell death in the penile cavernosum tissue of male rats in the hypoandrogenic state.Methods:We equally randomized 36 10-week-old SD male rats into six groups:4-week sham-operation(4-wk SO),8-week sham-operation(8-wk SO),4-week castration(4-wk C),8-week castration(8-wk C),4-week castration+testosterone replacement(4-wk C+T),and 8-week castration+T replacement(8-wk C+T).The rats in the SO groups received incision of the scrotal skin with preservation of the testis and epididymis,those in the C groups underwent bilateral orchiectomy and epididymectomy,and those in the C+T groups were subcutaneously injected with T propionate at 3 mg/kg qd alt.We measured the ratio of maximum intracavernous pressure to mean arterial pressure(ICPmax/MAP),the concentration of serum T and the level of nitric oxide(NO),and determined the expressions of active caspase-1 and caspase-3 in the penile cavernosum of all the animals.Results:The ICPmax/MAP ratio,ser-um T and NO levels and smooth muscle/collagen ratio were significantly lower in the C than in the SO and C+T groups(all P＜0.05).The rats in the 4-wk C group,compared with those in the SO group,showed dramatic increases in the rates of endothelial cell pyroptosis([15.31±0.55]％vs[0.78±0.53]％,P＜0.01),endothelial cell apoptosis([16.32±0.97]％vs[0.88±0.39]％,P＜0.01),total cell pyroptosis([9.67±0.49]％vs[1.53±0.24]％,P＜0.01)and total cell apoptosis([11.27±0.94]％vs[1.68±0.15]％,P＜0.01)in the penile cavernous tissue,and so did those of the 8-wk C group in the rates of endothelial cell pyroptosis([27.37±0.65]％vs[1.02±0.65]％,P＜0.01),endothelial cell apoptosis([24.27±0.54]％vs[1.00±0.63]％,P＜0.01),total cell pyroptosis([14.85±0.55]％vs[1.72±0.52]％,P＜0.01)and total cell apoptosis([15.92±0.53]％vs[1.27±0.31]％,P＜0.01).The rats of the 8-wk C group exhibited an even more signifi-cant elevation than those of the 4-wk C group in the rates of endothelial cell pyroptosis([27.37±0.65]％vs[15.31±0.55]％,P＜0.05)and endothelial cell apoptosis([24.27±0.54]％vs[16.32±0.97]％,P＜0.05).Conclusion:Pyroptosis and apoptosis are the main modes of death of endothelial cells in the penile cavernosum of male rats after 4 weeks of castration and,with the progression of the disease,both increase with minimally expressed caspase-1 and caspase-3 in the smooth muscle cells.Endothelial cells and smooth muscle cells have different modes of death in different stages of hypoandrogenism.