• Molecules and Cells
• /
• v.25 no.2
• /
• pp.242-246
• /
• 2008

To assess the role of $\alpha_{1G}$ T-type $Ca^{2+}$ channels in neuropathic pain after L5 spinal nerve ligation, we examined behavioral pain susceptibility in mice lacking $Ca_{V}3.1$ (${\alpha}_{1G}{^{-/-}}$), the gene encoding the pore-forming units of these channels. Reduced spontaneous pain responses and an increased threshold for paw withdrawal in response to mechanical stimulation were observed in these mice. The ${{\alpha}_{1G}}^{-/-}$ mice also showed attenuated thermal hyperalgesia in response to both low-(IR30) and high-intensity (IR60) infrared stimulation. Our results reveal the importance of ${\alpha}_{1G}$ T-type $Ca^{2+}$ channels in the development of neuropathic pain, and suggest that selective modulation of ${\alpha}_{1G}$ subtype channels may provide a novel approach to the treatment of allodynia and hyperalgesia.

• Korean Journal of Pharmacognosy
• /
• v.44 no.1
• /
• pp.60-69
• /
• 2013

The worldwide prevalence and severity of allergic diseases including atopic and contact dermatitis has increased dramatically over the past decade, especially in developed countries. Mast cells are important effector cells in allergic reactions. The purpose of this study was undertaken to investigate the anti-allergic and anti-pruritic effects of Diospyros lotus leaf extract (DLE). DLE was prepared by extracting with distilled water. In the present study, we investigated the effect of DLE on the production of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-$1{\beta}$ (IL-$1{\alpha}$) and histamine in rat peritoneal mast cells (RPMCs), and on the skin lesion, leukocyte infiltration and scratching behavior in mice. Phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187 significantly increased TNF-${\alpha}$ and IL-$1{\beta}$ production compared with media control. However, TNF-${\alpha}$ and IL-6 production increased by PMA plus A23187 treatment were significantly inhibited by DLE in a dose-dependent manner. DLE also inhibited the histamine release from RPMCs stimulated by compound 48/80, which promotes histamine release. Moreover, DLE administration had an inhibitory effects on the scratching behavior induced by pruritogen (compound 48/80, histamine) in ICR mice. Furthermore, DLE inhibited the skin lesions, inflammatory and mast cells in hairless mice sensitized by 2,4-dinitrofluorobenzene (DNFB). DLE administration reduced the IL-4 and IgE production induced by DNFB sensitization in hairless mice. These results suggest that DLE has a potential use as a herb medicine for treatment against allergy and pruritus-related disease.

• The Korean Journal of Physiology and Pharmacology
• /
• v.27 no.4
• /
• pp.325-331
• /
• 2023

α₁-adrenoceptors link via the G-protein Gq/G₁₁ to both Ca²⁺ entry and release from stores, but may also activate Rho kinase, which causes calcium sensitization. This study aimed to identify the subtype(s) of α₁-adrenoceptor involved in Rho kinase-mediated responses in both rat aorta and mouse spleen, tissues in which contractions involve multiple subtypes of α₁-adrenoceptor. Tissues were contracted with cumulative concentrations of noradrenaline (NA) in 0.5 log unit increments, before and in the presence of an antagonist or vehicle. Contractions produced by NA in rat aorta are entirely α₁-adrenoceptor mediated as they are competitively blocked by prazosin. The α_1A-adrenoceptor antagonist RS100329 had low potency in rat aorta. The α_1D-adrenoceptor antagonist BMY7378 antagonized contractions in rat aorta in a biphasic manner: low concentrations blocking α_1D-adrenoceptors and high concentrations blocking α_1B-adrenoceptors. The Rho kinase inhibitor fasudil (10 µM) significantly reduced aortic contractions in terms of maximum response, suggesting inhibition of α_1B-adrenoceptor mediated responses. In the mouse spleen, a tissue in which all 3 subtypes of α₁-adrenoceptor are involved in contractions to NA, fasudil (3 µM) significantly reduced both early and late components to the NA contraction, the early component involving α_1B- and α_1D-adrenoceptors, and the late component involving α_1B- and α_1A-adrenoceptors. This suggests that fasudil inhibits α_1B-adrenoceptor mediated responses. It is concluded that α_1D- and α_1B-adrenoceptors interact in rat aorta and α_1D-, α_1A- and α_1B-adrenoceptors interact in the mouse spleen to produce contractions and these interactions suggest that one of the receptors preferentially activates Rho kinase, most likely the α_1B-adrenoceptor.

• The Korean Journal of Pharmacology
• /
• v.30 no.2
• /
• pp.243-254
• /
• 1994

Inflammatory diseases, allergic and asthmatic disorders are caused by the mediator release from the activation of the phospholipase C (PLC), phospholipase D (PLD), methyltransferase or adenylate cyclase etc. during IgG or IgE cross-linking of high affinity receptors on mast cells or basophil surface. One important enzyme activated after IgG or IgE receptor cross-linking is PLD, the enzyme which converts phosphatidylcholine (PC) to phosphatidic acid (PA). Under the hypothesis that these may be some differences in mediator release according to the difference in PLD activity, we attempted to confirm the ginseng saponin effects on the PLD activity. We examined the PLD activity during the passively sensitized mast cell activation in the presence of single component of ginsenosides $(Rc,\;Rg_1,\;Rg_2,\;Rg_3)$. We also measured the amount of mediators (histamine and leukotrienes) released by stimulating with ovalbumin (OA) or calcium ionophore (CaI), Guinea Pig lung mast cells were purified using enzyme digestion, count current elutriation, and discontinuous Percoll density gradient. In purified mast cells prelabeled with $[^3H]$ arachidonic acid or $[^3H]$ palmitic acid, PLD activity was assessed more directly by the production of labeled PEt by PLD-mediated transphosphatidylation in the presence of ethanol. Histanine release was determined by Spectrophotofluorometry, and leukotrienes by radioimmunoassay. The PLD activity during the passively sensitized mast cell activation is increased up to $3{\sim}5times$. The PLD activity during the passively sensitized mast cell activation in the presence of all ginsenosides is decreased up to $4{\sim}11$ times. $Rg_l\;and\;Rg_2$ ginsenoside pretreatment decreased histamine and leukotrienes by 50% in the OA-induced or by 40% in the Cal-induced mast cell after passively sensitization. Rc pretreatment poorly decreased histamine but leukotrienes decreased by 70% in the OA-induced or by 35% in the Cal-induced mast cell. $Rg_3$ ginsenoside pretreatment increased histamine release without challenging OA or Cal but leukotrienes decreased. These observations indicate that single unit of ginsenosldes may be an important contributor to inhibit the release of histamine and leukotrienes in the guinea pig lung mast cells, that inhibits the PLD-mediated formation of DAG evoked by mast cell activation.

• Biomolecules & Therapeutics
• /
• v.21 no.1
• /
• pp.29-34
• /
• 2013

The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor family of cytokines. TRAIL selectively induces apoptotic cell death in various tumors and cancer cells, but it has little or no toxicity in normal cells. Agonism of TRAIL receptors has been considered to be a valuable cancer-therapeutic strategy. However, more than 85% of primary tumors are resistant to TRAIL, emphasizing the importance of investigating how to overcome TRAIL resistance. In this report, we have found that nemadipine-A, a cell-permeable L-type calcium channel inhibitor, sensitizes TRAIL-resistant cancer cells to this ligand. Combination treatments using TRAIL with nemadipine-A synergistically induced both the caspase cascade and apoptotic cell death, which were blocked by a pan caspase inhibitor (zVAD) but not by autophagy or a necrosis inhibitor. We further found that nemadipine-A, either alone or in combination with TRAIL, notably reduced the expression of survivin, an inhibitor of the apoptosis protein (IAP) family of proteins. Depletion of survivin by small RNA interference (siRNA) resulted in increased cell death and caspase activation by TRAIL treatment. These results suggest that nemadipine-A potentiates TRAIL-induced apoptosis by down-regulation of survivin expression in TRAIL resistant cells. Thus, combination of TRAIL with nemadipine-A may serve a new therapeutic scheme for the treatment of TRAIL resistant cancer cells, suggesting that a detailed study of this combination would be useful.