Objective A calcium-activated chloride current （ICl（Ca）） has been observed in medium-sized sensory neurons of the dorsal root ganglion （DRG）. Axotomy of the sciatic nerve induces a similar current in the majorit...Objective A calcium-activated chloride current （ICl（Ca）） has been observed in medium-sized sensory neurons of the dorsal root ganglion （DRG）. Axotomy of the sciatic nerve induces a similar current in the majority of medium and large diameter neurons. Our aim is to identify the molecule（s） underlying this current. Methods Using conventional and quantitative RT-PCR, we examined the expression in DRG of members of three families of genes, which have been shown to have latch） current inducing properties. Results We showed the detection of transcripts representing several members of these families, i.e. chloride channel calciumactivated （CLCA）, Bestrophin and Tweety gene families in adult DRG, in the normal state and 3 d after sciatic nerve section, a model for peripheral nerve injury. Conclusion Our analysis revealed that that mBestl and Tweety2 appear as the best candidates to play a role in the injury-induced Icl（Ca） in DRG neurons.展开更多
Objective To investigate what effects BmKAS 1 (a polypeptide purified from the Chinese scorpion Buthus martensi Karsch [BmK] and named as BmK activator of skeletal muscle ryanodine receptor) and its upstream mi...Objective To investigate what effects BmKAS 1 (a polypeptide purified from the Chinese scorpion Buthus martensi Karsch [BmK] and named as BmK activator of skeletal muscle ryanodine receptor) and its upstream mixture BmK1 3 2 have on Na + channels in dorsal root ganglion (DRG) small diameter neurons Methods The whole cell patch clamp technique was used to investigate the effects of BmKAS 1 and BmK1 3 2 on Na + current in rat small diameter DRG neurons Results About 50% peak Na + current was suppressed by 10?μg/ml of BmK1 3 2 1 62?μg/ml of BmKAS 1 also blocked 50% peak Na + current, and there was an obvious dose dependent relationship Conclusion Both BmK1 3 2 and BmKAS 1 have a blocking effect on Na + channels, and this may one of the mechanisms for the analgetic effect of BmK1 3 2 and BmKAS 1展开更多
Objective Melittin （MEL） is a major component of bee venom and can produce both persistent spontaneous nociception and pain hypersensitivity when injected subcutaneously in the periphery. The present study aimed to ...Objective Melittin （MEL） is a major component of bee venom and can produce both persistent spontaneous nociception and pain hypersensitivity when injected subcutaneously in the periphery. The present study aimed to examine the roles of transient receptor potential canonical （TRPC） channels in mediation of MEL-indueed activation of primary nociceptive cells. Methods Whole-cell patch-clamp and laser scanning confocal calcium detection were used to evalu- ate the effects of SKF-96365, a TRPC inhibitor, applied on the acutely isolated dorsal root ganglion （DRG） cells of rat, on MEL-induced increase in intracellular calcium concentration （[Ca2＋]i） and inward current. Results Under voltage- clamp mode, 43.9% （40/91） DRG cells were evoked to give rise to the inward current by 2 pmol/L MEL, which could be significantly suppressed by 3 doses of SKF-96365 （1, 5 and 10μmol/L） in a dose-dependent manner. Of the other 210 cells, 67.6% responded to MEL with an intracellular Ca2＋ rise, as revealed by confocal calcium imaging. Of these MEL- sensitive cells, 46.5% （66/142） were suppressed by the highest dose of SKF-96365. Conclusion MEL-induced activation of small to medium-sized DRG cells can be suppressed by SKF-96365, suggesting the involvement of TRPC channels in the mediation of MEL-induced activation of primary nociceptive cells.展开更多
文摘Objective A calcium-activated chloride current （ICl（Ca）） has been observed in medium-sized sensory neurons of the dorsal root ganglion （DRG）. Axotomy of the sciatic nerve induces a similar current in the majority of medium and large diameter neurons. Our aim is to identify the molecule（s） underlying this current. Methods Using conventional and quantitative RT-PCR, we examined the expression in DRG of members of three families of genes, which have been shown to have latch） current inducing properties. Results We showed the detection of transcripts representing several members of these families, i.e. chloride channel calciumactivated （CLCA）, Bestrophin and Tweety gene families in adult DRG, in the normal state and 3 d after sciatic nerve section, a model for peripheral nerve injury. Conclusion Our analysis revealed that that mBestl and Tweety2 appear as the best candidates to play a role in the injury-induced Icl（Ca） in DRG neurons.
基金ThisprojectwassupportedbytheNationalNaturalScienceFoundationofChina (No 3 9870 70 2 ) theNationalDrugFoundationofChina(No
文摘Objective To investigate what effects BmKAS 1 (a polypeptide purified from the Chinese scorpion Buthus martensi Karsch [BmK] and named as BmK activator of skeletal muscle ryanodine receptor) and its upstream mixture BmK1 3 2 have on Na + channels in dorsal root ganglion (DRG) small diameter neurons Methods The whole cell patch clamp technique was used to investigate the effects of BmKAS 1 and BmK1 3 2 on Na + current in rat small diameter DRG neurons Results About 50% peak Na + current was suppressed by 10?μg/ml of BmK1 3 2 1 62?μg/ml of BmKAS 1 also blocked 50% peak Na + current, and there was an obvious dose dependent relationship Conclusion Both BmK1 3 2 and BmKAS 1 have a blocking effect on Na + channels, and this may one of the mechanisms for the analgetic effect of BmK1 3 2 and BmKAS 1
基金supported by thegrants from National Natural Science Foundation of China (No. 30770668, 81070899)Beijing Natural Science Foundation (No. 7102019)Natural Science Foundation of Education Committee of Beijing Municipality, China (No. KM201010025005)
文摘Objective Melittin （MEL） is a major component of bee venom and can produce both persistent spontaneous nociception and pain hypersensitivity when injected subcutaneously in the periphery. The present study aimed to examine the roles of transient receptor potential canonical （TRPC） channels in mediation of MEL-indueed activation of primary nociceptive cells. Methods Whole-cell patch-clamp and laser scanning confocal calcium detection were used to evalu- ate the effects of SKF-96365, a TRPC inhibitor, applied on the acutely isolated dorsal root ganglion （DRG） cells of rat, on MEL-induced increase in intracellular calcium concentration （[Ca2＋]i） and inward current. Results Under voltage- clamp mode, 43.9% （40/91） DRG cells were evoked to give rise to the inward current by 2 pmol/L MEL, which could be significantly suppressed by 3 doses of SKF-96365 （1, 5 and 10μmol/L） in a dose-dependent manner. Of the other 210 cells, 67.6% responded to MEL with an intracellular Ca2＋ rise, as revealed by confocal calcium imaging. Of these MEL- sensitive cells, 46.5% （66/142） were suppressed by the highest dose of SKF-96365. Conclusion MEL-induced activation of small to medium-sized DRG cells can be suppressed by SKF-96365, suggesting the involvement of TRPC channels in the mediation of MEL-induced activation of primary nociceptive cells.
