• The Korean Journal of Physiology
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• 제26권2호
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• pp.113-122
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• 1992

It is well known that chromaffin cells of adrenal medulla secrete catecholamine in response to sympathetic nerve activation and the influx of $Ca^{2+}$ through the voltage dependent $Ca^{2+}$ channels (VDCC) in the cell membrane do a major role in this secretory process. In this study, we explored the effect of divalent cations on VDCC of rat chromaffin cells. Rat (Sprague-Dawley rat, 150-250 gm) chromaffin cells were isolated and cultured. Standard giga seal, whole cell recording techniques were employed to study $Ca^{2+}$ current with external and internal solutions that could effectively isolate VDCC currents $(NMG\;in\;external\;and\;TEA\;and\;Cs^{2+}\;in\;internal\;solution)$. The voltage dependence and the inactivation time course of VDCC in our cells were identical to those of bovine chromaffin cells. A persistent inward current was first activated by depolarizing step pulse from the holding potential (H.P.) of -80 mV to -40 mV, increased to maximum amplitude at around +10 mV, and became smaller with progressively higher depolarizing pulses to reverse at around +60 mV. The inactivation time constant $(\tau)$, fitted from the long duration test potential (2 sec) was $1295.2{\pm}126.8$ msec $(n=20,\;1\;day\;of\;culture,\;mean\;{\pm}S.E.M.)$ and the kinetic parameters were not altered along the culture duration. Nicardipine $(10\;{\mu}M)$ blocked the current almost completely. Among treated divalent cations such as $Cd^{2+},\;Co^{2+},\;Ni^{2+},\;Zn^{2+}\;and\;,Mn^{2+},\;Cd^{2+}$ was the most potent blocker on VDCC. When the depolarizing step pulse from -80 mV to 10 mV was applied, the equilibrium dissociation constant $(K_d)$ of $Cd^{2+}\;was\;39\;{\mu}M,\;K_d\;of\;Co^{2+}\;was\;100\;{\mu}M\;and\;K_d\;of\;Ni^{2+}];was];780{\mu}M.$ The principal findings of this study are as follows. First, the majority of $Ca^{2+}$ channels in rat chromaffin cells are well classified to L-type $Ca^{2+}$ channel in the view of kinetics and pharmacology. Second, all divalent cations tested could block the $Ca^{2+}$ current and the most potent blocker among the tested was $Cd^{2+}$.

• Journal of Acupuncture Research
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• 제20권2호
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• pp.42-49
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• 2003

Purpose : In order to study the effectiveness of East-West pain treatment on central poststroke pain(CPSP), we evaluated its effect on alleviation of pain and rehabilitation of CPSP patients who were treated with eletroacupuncture and west pain treatment for four weeks. Methods : Twenty four patients diagnosed by their pain characteristics of central pain form stroke were treated with sympathetic nerve block, gabapentin, amitriptyline, and electroacupuncture for four weeks. Pain intensity through the visual analogue scale(VAS), and improvements of mobility and rehabilitation through the modified Barthel index(MBI) and Rankin scale(RS), respectively, before and after pain treatment were also assessed. Results : VAS pain scores were significantly improved from $7.7{\pm}1.7$ to $4.4{\pm}2.0$ with pain treatment(p<0.05). In accordance with improvement of ain scores, RS and MBI scores ere also improved from $2.88{\pm}0.95$ to $2.13{\pm}1.01$ and from $83.0{\pm}16.9$ to $94.7{\pm}9.5$(p<0.05), respectively, with pain treatment(p<0.05). Conclusions : It was suggested that the active pain treatment was contributed to the rehabilitation of CPSP patients, resulting in improvement of quality of life of CPSP patients. Futhermore, East pain treatment in combination with West pain treatment may be useful modality to alleviate CPSP.