OBJECTIVETo detect the expressions of transforming growth factor-beta1 (TGF-beta1), Desmin and CD34 in the penile corpus cavernosum of SD rats in different age groups.

METHODSWe randomly selected 10 SD rats in each of the 2-, 5- and 20-month age groups, harvested their penile corpus cavernosum tissues under ether anesthesia, and detected the mRNA and protein expressions of TGF-beta1, Desmin and CD34 by RT-PCR and immunohistochemistry.

RESULTSThe results of RT-PCR showed the mRNA expressions of TGF-beta1, Desmin and CD34 in the corpus cavernosum tissues, with significant differences between every two groups (P < 0.01). The TGF-beta1 protein was mainly expressed in the trabeculae and around the arteries of the corpus cavernosum for membrane and cytoplasm staining, the Desmin protein mainly in the membrane and cytoplasm for muscle tissue staining; and the CD34 protein mainly in the vascular and sinusoidal endothelia. The mRNA expression of TGF-beta1 was correlated positively (r = 0.944, P < 0.01) while those of Desmin and CD34 negatively with the age of the rats (r = -0.947, P < 0.01; r = -0.934, P < 0.01). And the mRNA expressions of both Desmin and CD34 had a significant correlation with that of TGF-beta1 (r = -0.888, P < 0.01; r = -0.887, P < 0.01).

CONCLUSIONWith the increase of age, the expression of TGF-beta1 is significantly up-regulated, while those of Desmin and CD34 significantly down-regulated in the corpus cavernosum tissues, and it is negatively correlated with the latter two. TGF-beta1 is an important influencing factor on ED.