[Changes of gap junction in penile cavernous smooth muscle cells of hypertensive rats]

To compare the changes of the intercellular conjunction in penile cavernous tissues between spontaneously hypertensive rats (SHR) and normotensive ones, and to study the relation of blood pressure with erectile function.

After apomorphine (APO) injection, we observed penile erections in SHR (SHR group, n=5) and Wistar-Kyoto rats (WKY group, n=5), studied the ultrastructure of the cell-to-cell conjunction between the penile cavernous smooth muscle cells with a transmission electrical microscope, and examined the expression of mRNA and Connexin 43 protein by RT-PCR and immunohistochemistry.

The erectile frequency in the SHR group was significantly lower than in the WKY group. The smooth muscle cells were decreased and the collagen fibers between the smooth muscle cells were increased in the SHR group. The expression of mRNA and Connexin 43 protein in the cavernous tissues was significantly lower in the SHR group than in the WKY group (P < 0.05).

Hypertension affects penile erection, and the pathological changes of the cell-to-cell conjunction between the penile cavernous smooth muscle cells may be one of the important mechanisms of erectile dysfunction associated with hypertension.