Résumé
The present study investigated the participation of D-serine and NR2 in antinociception produced by blockade of central erythropoietin-producing hepatocellular carcinoma (Eph) A4 (EphA4) signaling in rats with trigeminal neuropathic pain. Trigeminal neuropathic pain was modeled in male Sprague-Dawley rats using mal-positioned dental implants. The left mandibular second molar was extracted under anesthesia, and a miniature dental implant was placed to induce injury to the inferior alveolar nerve. Our current findings showed that nerve injury induced by malpositioned dental implants significantly produced mechanical allodynia; additionally, the inferior alveolar nerve injury increased the expression of D-serine and NR2 subunits in the ipsilateral medullary dorsal horn (trigeminal subnucleus caudalis). Intracisternal administration of EphA4-Fc, an EphA4 inhibitor, inhibited nerve injury-induced mechanical allodynia and upregulated the expression of D-serine and NR2 subunits. Moreover, intracisternal administration of D-amino acids oxidase, a D-serine inhibitor, inhibited trigeminal mechanical allodynia. These results show that D-serine and NR2 subunit pathways participate in central EphA4 signaling after an inferior alveolar nerve injury.Therefore, blockade of D-serine and NR2 subunit pathways in central EphA4 signaling provides a new therapeutic target for the treatment of trigeminal neuropathic pain.
Résumé
<p><b>OBJECTIVE</b>To evaluate the efficacy of Bawu Decoction (, BWD, Palmul-tang in Korean) against benign prostatic hyperplasia (BPH).</p><p><b>METHODS</b>Twenty-four male Wistar rats were divided into 4 groups, with 6 rats in each group. The 4 study groups included sham-operated group (CON), BPH model group, fifinasteride-treated group, and BWD-treated group. All the groups except CON group received a subcutaneous injection of 10 mg/kg of testosterone, while CON group received saline. Finasteride at a dose of 5 mg/kg was administered to the finasteride-treated group for a period of 4 weeks. BWD group received BWD at a dose of 200 mg/kg for 4 weeks. The prostatic weight, prostate weight to body weight ratio, relative prostate weight ratio, serum testosterone and dihydrotestosterone (DHT) level, and histological analysis of prostatic tissue were analyzed.</p><p><b>RESULTS</b>Compared to BPH model group, BWD administration was associated with reductions in prostatic weight, prostate and relative prostate weight ratio weight to body weight ratio (P<0.05). The concentration of serum testosterone and DHT were higher in BPH group compared with CON group (P<0.05). Administration of finasteride and BWD suppressed the elevation of serum testosterone and DHT levels signifificantly (both P<0.05). In addition, BWD suppressed the growth of prostatic tissue (P<0.05).</p><p><b>CONCLUSION</b>BWD has suppressant effects on development of BPH through inhibition of serum testosterone and DHT.</p>
Résumé
We investigated the role of central P2X receptors in inflammatory pain transmission in the orofacial area in rats. Experiments were carried out using male Sprague-Dawley rats weighing 230-280g. Complete Freund's adjuvant (CFA, 40 microL) was applied subcutaneously to the vibrissa pad to produce inflammatory pain. The intracisternal administration of iso-PPADS tetrasodium salt, a non-selective P2X receptor antagonist, A317491 sodium salt hydrate, a P2X2/3 receptor antagonist, 5-BDBD, a P2X4 receptor antagonist, or A438079 hydrochloride, a P2X7 receptor antagonist, was performed 5 days after CFA injection. Subcutaneous injections of CFA produced increases in thermal hypersensitivity. Intracisternal injections of iso-PPADS (25 microg) or A438079 (25 or 50 microg) produced significant anti-hyperalgesic effects against thermal stimuli compared to the vehicle group. A317491 or 5-BDBD did not affect the head withdrawal latency times in rats showing an inflammatory response. Subcutaneous injections of CFA resulted in the up-regulation of OX-42, a microglia marker, and GFAP, an astrocyte marker, in the medullary dorsal horn. The intracisternal administration of A438079 reduced the numbers of activated microglia and astrocytes in the medullary dorsal horn. These results suggest that a blockade of the central P2X7 receptor produces antinociceptive effects, mediated by inhibition of glial cell function in the medullary dorsal horn. These data also indicate that central P2X7 receptors are potential targets for future therapeutic approaches to inflammatory pain in the orofacial area.