Nerve Regeneration and Detrusor Contractility after Muscle Precursor Cells Implantation in Unilateral Pelvic Nerve Transected Rat

Im, Chang Min; Kwon, Dong Deuk; Ryu, Soo Bang

Abstract

Purpose
Preliminary data suggest that muscle precursor cells (MPCs) play a role in the repair of injured tissues by responding to the release of unknown growth factors, which subsequently induce their differentiation toward a given lineage, such as a nerve cell. The author explored the potential use of these cells for facilitating the regeneration of the peripheral pelvic autonomic nerve.
Materials and Methods
MPCs were isolated from the gastrocnemius muscle of normal rats, which were purified via the preplate technique. In this study, 15 male Sprague-Dawley rats weighting 250 to 300 grams were used. Three experimental groups were included: a control group (C, n=5), a unilateral pelvic nerve transected group, with a sham (Hank's balanced salt Solution) injection (S, n=5), and a unilateral pelvic nerve transected group, with MPCs injections (3x10(5)cells) at the site of transection (M, n=5). Two weeks after surgery, a polyethylene tube-50 connected to a pressure transducer was inserted into the dome of the bladder, and the intravesical pressures measured during electrical stimulation (20Hz, 0.05ms, 10v) of the proximal part of the transection of preganglionic pelvic nerve. Then, the rats were sacrificed, and the major pelvic ganglia (MPG) removed for immunohistochemistry of enkephalin.
Results
The maximal intravesical pressures for the C, M and S groups were 28.5cmH2O, 13.5cmH2O and 8.6cmH2O, respectively (p<0.001). The pressure difference between the maximal pressure after electrical stimulation and the basal pressure before electrical stimulation for the C, M and S groups were 23.8cmH2O, 8.9cmH2O and 4.6cmH2O, respectively (p< 0.001). The intensity of pericellular immunoreactivity for enkephalin from the removed MPG was more markedly decreased in the S than C group, but was more markedly increased in the M than S group.
Conclusions
MPCs can promote peripheral autonomic nerve regeneration, with good correlations between the functional and immunohistochemical results of neurorecovery effect of MPCs.