[Immediate and delayed intracavernous injection of bone marrow mesenchymal stem cells to improve erectile function in rats with cavernous nerve injury].

OBJECTIVE

To explore the effects of immediate and delayed intracavernous injection of bone marrow mesenchymal stem cells (BM-MSCs) on neurogenic erectile dysfunction (NED) induced by bilateral cavernous nerve injury in Sprague-Dawley (SD) rats.

METHODS

BM-MSCs isolated from male SD rats were cultured and identified. Twenty-eight 8-week-old male SD rats were randomly divided into four groups, sham operation, NED model control, BM-MSCs immediate, and BM-MSCs delayed, and NED models were established in the latter three groups by crushing the bilateral cavernous nerves. The rats in the sham operation and model control groups were injected intracavernously with placebo while those in the latter two with BM-MSCs immediately or 2 weeks after modeling. At 12 weeks after operation, the penile function of the rats was assessed according to the penile intracavernous pressure (ICP), mean arterial pressure (MAP), and ICP/MAP ratio obtained from different groups of rats. Then, all the animals were sacrificed and the penile cavernosal tissue collected for histological analysis.

RESULTS

At 12 weeks after modeling, both ICP and ICP/MAP were significantly increased in the BM-MSCs immediate and delayed groups as compared with those in the model control (P <0.05), and so were the ratio of smooth muscle to collagen (P <0.05) and the smooth muscle content in the corpus cavernosum (P <0.05), and the number of neurofilament (NF)-positive nerve fibers (P <0.05) and the expression of neuronal nitric oxide synthase (nNOS) in the dorsal nerves of the midshaft penis (P <0.05).

CONCLUSIONS

Intracavernous injection of BM-MSCs can improve erectile function in rats with bilateral cavernous nerve injury by elevating the smooth muscle-collagen ratio and smooth muscle content in the corpus cavernosum and thus preventing its fibrosis as well as by increasing the number of NF-positive nerve fibers and expression of nNOS in the penile dorsal nerves.