The pathophysiological role of androgen deprivation in male sexual dysfunction remains controversial, and this is especially true at the molecular level. We investigated the effect of androgen deprivation on the changes of proteins in the penile corpus cavernosum of castrated rabbits by the proteomic approach.

New Zealand white male rabbits (2.5-3kg) were divided into 2 groups: the control group with 5 rabbits and the bilateral orchiectomized group. The bilateral orchiectomized group was divided into the post-operative 4 weeks group (group 1), and the 8 weeks group (group 2) with 5 rabbits in groups 1 and 2, respectively. The penile corpus cavernosum was partly excised at 4 or 8 weeks from the beginning of the experiment. Conventional proteomics was performed with high resolution 2-D gel electrophoresis; this was followed by computational image analysis and protein identification with using mass spectrometry.

A comparison of the corpus cavernosum of the orchiectomized group with the control group showed that nine proteins had a changed expression. Glycerol-3-phosphate dehydrogenase and F-actin binding protein were under-expressed in groups 1 and 2, and myosin regulatory light chain 2, tropomyosin β chain and tropomyosin 1 were significantly under-expressed in group 1 and they were insignificantly over-expressed in group 2. In addition there were 4 proteins that were insignificantly under-expressed; skeletal muscle myosin heavy chain MyHC-EO/III, a protein that was similar to suppressor of cytokine signaling 6 isoform, myosin light chain 1 and heat shock 27kDa protein 1.

This data suggests that changes of proteins, and especially tropomyosin 1, mean there is processing of the cellular apoptosis pathway in the orchiectomized rabbits' corpus cavernosum. However more information is needed about human corpus cavernosal tissue.