ABSTRACT
Objective@#To explore the expression of the N-methyl-D-aspartate (NMDA) receptor in the rat model of orchialgia and its possible mechanisms.@*METHODS@#According to Yoshioka's method, the male rats in the control group were injected with 0.2 ml saline, and those in the experimental group with 0.2 ml 2% acetic acid solution. Then we tested the behavioral responses of the rats and determined the expressions of the subunits NR1 and NR2B of the NMDA receptor in the dorsal root ganglion and spinal dorsal horn by Western blot, RT-qPCR and immunofluorescence staining.@*RESULTS@#The withdrawal latency was decreased in the model rats, reaching the lowest value at 4 hours after modeling, significantly lower than in the controls (［4.15 ± 0.84］ vs ［12.32 ± 1.05］, P 0.05).@*CONCLUSIONS@#The NMDA receptor plays an important role in pathogenesis of orchialgia in rats. In the early stage of pain, upregulating the expression of the subunit NR2B of the NMDA receptor can mediate peripheral hyperalgesia and consequently orchialgia.
ABSTRACT
Objective@#To explore the expressions of transient receptor potential vanilloid 1 (TRPV1) and TRP ankyrin 1 (TRPA1) in the dorsal root ganglion (DRG) and their action mechanisms in the rat model of orchialgia.@*METHODS@#The models of orchialgia were established in male SD rats by injection of 2% acetic acid into the testis. Then the number of spontaneous pain responses and withdrawal latency in the model rats were recorded by behavioral tests and the expressions of TRPV1 and TRPA1 in T13－L1 DRGs determined by RT-qPCR, Western blot and immunofluorescence staining.@*RESULTS@#Compared with the normal control rats, the orchialgia models showed a significant increase in the number of spontaneous pain responses (0.13 ± 0.35 vs 22.63 ± 3.42, P<0.01) and a decrease in the withdrawal latency at 4 hours after injection (［12.75 ± 1.50］ vs ［4.85 ± 1.00］ s, P<0.05). The mRNA expressions of both TRPV1 and TRPA1 were observed in the membrane of the neurons in the DRG, the former increased by 1.77 times and the latter by 1.75 times that of the control (P<0.05).@*CONCLUSIONS@#The expressions of TRPV1 and TRPA1 were up-regulated in the DRG of the rat models of orchialgia, which may be involved in the allodynia and hyperalgesia of the rats.
Subject(s)
Animals , Male , Rats , Acetic Acid , Ganglia, Spinal , Metabolism , Hyperalgesia , Metabolism , Membrane Glycoproteins , Oxidoreductases , Rats, Sprague-Dawley , TRPA1 Cation Channel , Metabolism , TRPV Cation Channels , Metabolism , Testicular Diseases , Metabolism , Up-RegulationABSTRACT
A patient referred to our hospital, diagnosed with left idiopathic chronic orchialgia, was evaluated with a thorough medical and psychiatric history, physical examination, scrotal ultrasound and magnetic resonance imaging. Conservative management failed. The patient had temporary pain relief after undergoing outpatient cord block three times. Microsurgical denervation of the left spermatic cord was operated in March, 2011. A pain questionnaire was used to determine efficacy before and after operation, and complete pain relief was noted at one week after operation. The follow up period was 12 months, at the end of which the pain score was still zero. No complications, including testicular atrophy and hydrocele, occurred. Microsurgical denervation of the spermatic cord can be a minimally invasive, safe and effective management option for treatment of idiopathic chronic orchialgia.