TAC‐302 promotes neurite outgrowth of isolated peripheral neurons and prevents bladder denervation related bladder dysfunctions following bladder outlet obstruction in rats

AIMS: To evaluate the ability of TAC-302, a cyclohexenoic fatty alcohol derivative, to enhance neurite outgrowth in cultured rat dorsal root ganglion (DRG) neurons, and the preventive effects of TAC-302 on bladder denervation-related storage and voiding dysfunctions in rats with bladder outlet obstruction (BOO). METHODS: Rat DRG neurons were cultured in the presence of TAC-302. Cell numbers and neurite lengths were quantified after a 24 h culture. BOO was achieved by partial ligature of the proximal urethra in female rats. BOO rats were divided into three groups and orally treated with vehicle of 3 or 30 mg/kg TAC-302 twice a day for 4 weeks. Cystometry was performed under conscious conditions. Immunohistochemical staining using anti-PGP9.5 of the bladder muscle layer was performed, and the innervation area was scored. RESULTS: TAC-302 significantly and dose-dependently increased neurite outgrowth in cultured DRG neurons. BOO rats showed a decreased innervation area in the urinary bladder compared to sham-operated rats. BOO-induced denervation of the urinary bladder was partially prevented by oral treatment with TAC-302. TAC-302 significantly reduced the frequency of non-voiding contraction (NVC) and residual urine volume (RUV) compared with the BOO vehicle group (P < 0.05). The innervation area score exhibited significant negative correlations with NVC and RUV, indicating that they increased according to the progression of denervation. CONCLUSIONS: Our data indicate that TAC-302 promotes neurite outgrowth in vitro. In addition, TAC-302 prevents BOO-induced bladder dysfunction in rats, and has a protective effect on bladder denervation.