Expressions of Erk1/2 and PKB/Akt in the corpus cavernosum of castrated rats

XU Chen-xiang; MAO Jun-biao; JIANG Rui

Abstract：Objective: To study the expressions of Erk1/2 and PKB/Akt in the corpus cavernosum of castrated rats and investi-gate their action mechanism in the development of erectile dysfunction (ED) after castration. Methods: We randomly divided 20 eight-week-old SD rats into Groups A (sham-operation) and B (castration), and, 4 weeks after the operation, determined the level of serum testosterone (T) and the expressions of P-Erk1/2 and P-PKB/Akt proteins (integrated optical density/area, IA/area) and those of Erk1/2 and PKB/Akt mRNA (Marker: GAPDH) in the corpus cavernosum of the rats by immunohistochemical staining and RT-PCR. Results: Four weeks after the operation, the serum T level was significantly decreased in Group B in comparison with A ([10.090±3.026] nmol/L versus [1.339±0.642] nmol/L, P < 0.05). Erk1/2 and PKB/Akt expressed in the corpus caverno-sum of both groups of rats. The expressions of Erk1 and Erk2 mRNA and P-Erk1/2 were significantly higher in Group B (0.840±0.062,0.876±0.141 and 0.142±0.020) than inA (0.479±0.090,0.599±0.100 and 0.119±0.029)(P<0.05).But no statistically significant differences were found in the expressions of PKB/Akt mRNA and P-PKB/Akt between Groups B (0.974±0.040 and 0.164±0.036) and A (0.942±0.054 and 0.162±0.025)(P<0.05). Conclusion: Erk1/2 and PKB/Akt expressed in the penile tissues of both castrated and sham-operation rats. The increased expression of P-Erk1/2 in the corpuscavernosum may be involved in the development of ED in castrated rats.