Comparative analysis of periprostatic implantation and intracavernosal injection of human adipose tissue-derived stem cells for erectile function recovery in a rat model of cavernous nerve injury

We compared periprostatic implantation (PPI) and intracavernosal injection (ICI) of human adipose tissue-derived stem cell (ADSC) to facilitate recovery of erectile function in a rat model of cavernous nerve (CN) injury.Bilateral CN dissection (BCND) was induced in Sprague-Dawley rats. After BCND 10 rats each were treated with PPI and/or ICI of ADSCs. After 4 weeks erectile responses to electric pelvic ganglion stimulation were studied. Each penis was evaluated in terms of the expression of neuronal nitric oxide synthase and smooth muscle content.The ratio of maximal intracavernosal pressure to mean arterial pressure was significantly decreased in the BCND group (24.5%) compared to the sham group (64.2%). PPI and ICI significantly improved erectile function (46.7% and 47.9%, respectively) compared to the BCND group. A combination of PPI and ICI (42.5%) did not afford any incremental effect on erectile function. After stem cell therapy, the expression of neuronal nitric oxide synthase increased slightly in the ICI group without statistical relevance, whereas the PPI and combination groups showed marginally significant increases (P = 0.08). In both the PPI and ICI groups, the smooth muscle content was similar to the sham group. The combination group showed remarkable increase in smooth muscle content to an extent greater than that seen when either treatment was given alone, although statistically not significant.PPI or ICI of ADSCs in a rat model of CN injury were equally effective in recovering penile erection, but may address different types of pathophysiology.