• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.147-147
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• 1993

신생쥐의 DRG 배양에서 접종후 1일째 neurite의 형성을 관찰할수 있었고 배양한 세포가 신경세포임을 확인하기 위하여 신경섬유에 대한 항체를 이용한 조직화학적 실험을 실시한 결과 붉게 염색된 세포를 볼 수 있었으므로 이 세포들이 DRG신경세포임을 확인할 수 있었다. 배양한 신경세포중 capsaicin에 대한 감수성을 갖는 신경세포군을 확인하기 위하여 cobalt stain 방법으로 실험한 결과 capsaicin에 대한 감수성율 갖는 신경세포룰 관찰할 수 있었고 비교를 위하여 함께 실험한 resiniferatoxin, KR 25018, 6-paradol, NE-19550, RDL-201등의 capsaicin 유사체들의 경우도 정도는 달리 하였으나 유사한 반응을 보였으므로 일차배양한 신경세포에 대한 작용이 capsaicin의 작용과 같을 가능성을 보여주었다. 진통효과 검정결과 진통효과가 있는 것으로 확인된 capsaicin 구조 유사체들인 resiniferatoxin, 6-paradol, NE-19550, RDL-201, KR-25018모두 농도 의존적인 반응을 보였다. 또한 칼슘 도입을 위해 요구되는 관능기로는 알킬측쇄와 P-위치의 수산기, 3-methoxy기 및 acyl amide 구조가 중요하였다. 알킬측쇄는 NVA의 경우처럼 탄소 8개 정도가 적당했으나 구조적으로 현저히 다른 치환기를 가진 resiniferatoxin이나 KR-25018의 경우에도 유효하였다. Vanillin환의 P-수산기도 필수적이었고 3-methoxy기의 존재시에는 칼슘 도입효과가 강하였다. Acyl amide 결합도 중요하나 필수적은 아니였다.

• Parasites, Hosts and Diseases
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• v.55 no.6
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• pp.587-599
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• 2017

The immune response against Trichinella spiralis at the intestinal level depends on the $CD4^+$ T cells, which can both suppress or promote the inflammatory response through the synthesis of diverse cytokines. During the intestinal phase, the immune response is mixed (Th1/Th2) with the initial predominance of the Th1 response and the subsequent domination of Th2 response, which favor the development of intestinal pathology. In this context, the glucocorticoids (GC) are the pharmacotherapy for the intestinal inflammatory response in trichinellosis. However, its therapeutic use is limited, since studies have shown that treatment with GC suppresses the host immune system, favoring T. spiralis infection. In the search for novel pharmacological strategies that inhibit the Th1 immune response (proinflammatory) and assist the host against T. spiralis infection, recent studies showed that resiniferatoxin (RTX) had anti-inflammatory activity, which decreased the serum levels of IL-12, $INF-{\gamma}$, $IL-1{\beta}$, $TNF-{\alpha}$, NO, and $PGE_2$, as well the number of eosinophils in the blood, associated with decreased intestinal pathology and muscle parasite burden. These researches demonstrate that RTX is capable to inhibit the production of Th1 cytokines, contributing to the defense against T. spiralis infection, which places it as a new potential drug modulator of the immune response.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.129-136
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• 2016

This study was performed to investigate whether an intra-articular injection of transient receptor potential vanilloid 1 (TRPV1) receptor agonist, resiniferatoxin (RTX) would alleviate behavioral signs of arthritic pain in a rat model of osteoarthritis (OA). We also sought to determine the effect of RTX treatment on calcitonin gene-related peptide (CGRP) expression in the spinal cord. Knee joint inflammation was induced by intra-articular injection of monosodium iodoacetate (MIA, $8mg/50{\mu}l$) and weight bearing percentage on right and left hindpaws during walking, paw withdrawal threshold to mechanical stimulation, and paw withdrawal latency to heat were measured to evaluate pain behavior. Intra-articular administration of RTX (0.03, 0.003 and 0.0003%) at 2 weeks after the induction of knee joint inflammation significantly improved reduction of weight bearing on the ipsilateral hindlimb and increased paw withdrawal sensitivity to mechanical and heat stimuli. The reduction of pain behavior persisted for 3~10 days according to each behavioral test. The MIA-induced increase in CGRP immunoreactivity in the spinal cord was decreased by RTX treatment in a dose-dependent manner. The present study demonstrated that a single intra-articular administration of RTX reduced pain behaviors for a relatively long time in an experimental model of OA and could normalize OA-associated changes in peptide expression in the spinal cord.

• Archives of Pharmacal Research
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• v.20 no.1
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• pp.93-95
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• 1997

The aim of the present study was to elucidate the mechanism of action of DA-5018 and to compare it with those of capasaicin, resiniferatoxin (ultrapotent capasaicin analog), and olvanil (systemic antinociceptive agent equipotent with capasaicin developed by Proctor & Gamble) (fig.1).

• Biomolecules & Therapeutics
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• v.27 no.5
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• pp.435-441
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• 2019

The capsaicin receptor TRPV1 (transient receptor potential vanilloid 1) has been an object of intense interest for pharmacological development on account of its critical role in nociception. In the course of structure activity analysis, it has become apparent that TRPV1 ligands may vary dramatically in the rates at which they interact with TRPV1, presumably reflecting differences in their abilities to penetrate into the cell. Using a fast penetrating agonist together with an excess of a slower penetrating antagonist, we find that we can induce an agonist response of limited duration and, moreover, the duration of the agonist response remains largely independent of the absolute dose of agonist, as long as the ratio of antagonist to agonist is held constant. This general approach for limiting agonist duration under conditions in which absolute agonist dose is variable should have more general applicability.

• Archives of Pharmacal Research
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• v.28 no.4
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• pp.405-412
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• 2005

A vanilloid receptor (VR1, now known as TRPV1) is an ion channel activated by vanilloids, including capsaicin (CAP) and resiniferatoxin (RTX), which are pungent ingredients of plants. Putative endogenous activators (anandamide and metabolites of arachidonic acid) are weak activators of VR1 compared to capsaicin and RTX, and the concentrations of the physiological condition of those activators are not sufficient to induce significant activation of VR1. One way to overcome the weak activation of endogenous activators would be the sensitization of VR1, with the phosphorylation of the channel being one possibility. The phosphorylation of VR1 by several kinases has been reported, mostly by indirect evidence. Here, using an in vivo phosphorylation method, the VR1 channel was shown to be sensitized by phosphorylation of the channel itself by multiple pathways involving PKA, PKC and acid. Also, in sensitizing VR1, BK appeared to show activation of PKC for the sensitization of VR1 by phosphorylation of the channel.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.1
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• pp.65-74
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• 2017

Here we investigated the central processing mechanisms of mechanical allodynia and found a direct excitatory link with low-threshold input to nociceptive neurons. Experiments were performed on male Sprague-Dawley rats weighing 230-280 g. Subcutaneous injection of interleukin 1 beta ($IL-1{\beta}$) ($1ng/10{\mu}L$) was used to produce mechanical allodynia and thermal hyperalgesia. Intracisternal administration of bicuculline, a gamma aminobutyric acid A ($GABA_A$) receptor antagonist, produced mechanical allodynia in the orofacial area under normal conditions. However, intracisternal administration of bicuculline (50 ng) produced a paradoxical anti-allodynic effect under inflammatory pain conditions. Pretreatment with resiniferatoxin (RTX), which depletes capsaicin receptor protein in primary afferent fibers, did not alter the paradoxical anti-allodynic effects produced by the intracisternal injection of bicuculline. Intracisternal injection of bumetanide, an Na-K-Cl cotransporter (NKCC 1) inhibitor, reversed the $IL-1{\beta}$-induced mechanical allodynia. In the control group, application of GABA ($100{\mu}M$) or muscimol ($3{\mu}M$) led to membrane hyperpolarization in gramicidin perforated current clamp mode. However, in some neurons, application of GABA or muscimol led to membrane depolarization in the $IL-1{\beta}$-treated rats. These results suggest that some large myelinated $A{\beta}$ fibers gain access to the nociceptive system and elicit pain sensation via $GABA_A$ receptors under inflammatory pain conditions.