RESUMO
Objective To study the changes of genitofemoral nerve (GFN) nuclear in dorsal root ganglion of unilateral cryptorchid rats. Methods Using retrograde tracing of horseradish peroxidase (HRP) and immunofluorescent double labeling, we observed GFN nucleus and calcitonin gene related peptide immunoreactivity (CGRP-IR) cells of the unilateral crytorchid rats induced by 17-β estradiol. Group A (n=12), unilateral cryptorchid; Group B (n=12), unilateral cryptorchid combined with GFN division at 30 d after birth, and Group C (n=10), control group. The GFN proximal ends of the 3 groups were labeled with HRP at post-birth 58 d. The rats were killed 48 h later, and the ganglia and spinal cord were removed, serial sections frozen in cryostat were cut, and HRP labeled neurons were counted and the CGRP-IR cells were double fluorescently labeled with antibody to CGRP and FICT.Results HRP-positive GFN was found in sensory nuclei of L1, L2 dorsal root ganglias and CGRP-IR cells in motor nuclei. The mean gray scale and positive unit of HRP-positive neurons of group A was obvious higher than that of group B and C (P＜0.05), but CGRP-IR cells were significantly less (P＜0.05). However, compared with group C, in group B HRP-positive neurons and CGRP-IR cells were not statistically significant different (P ＞0.05). Conclusions In rats with contralateral testicular impairment induced by unilateral cryptorchid, the sensory neurons increase and motor neurons decrease and its secretion of neurotransmitter CGRP is inhibited.