• Title/Summary/Keyword: Receptor model

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Anti-obese Effects and Signaling Mechanisms of Chaenomeles sinensis extracts in 3T3-L1 Preadipocytes and Obese Mice Fed a High-fat Diet (3T3L-1 지방전구세포와 고지방식이로 유도된 비만 마우스 모델에서 모과 추출물의 항비만 효과와 억제 기전)

  • Kim, Da-Hye;Kwon, Bora;Kim, Sang Jun;Kim, HongJun;Jeong, Seung-Il;Yu, Kang-Yeol;Kim, Seon-Young
    • Herbal Formula Science
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    • v.25 no.4
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    • pp.457-469
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    • 2017
  • Obesity is one of the most serious health problem because it induced numerous metabolic syndrome and increases the incidence of various disease, including diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer. In 3T3-L1 adipocytes, increases in reactive oxygens species (ROS) occur with lipid accumulation. NADPH oxidase, producing superoxide anion, may contribute to the development of obesity-associated insulin resistance and type 2 diabetes. In this study, we elucidated the effect of Chaenomeles sinensis koehne extract (CSE) against the development of obesity and the inhibition mechanisms in 3T3-L1 preadiocytes. CSE decreased triglyceride content and inhibited the expression of adipogenic transcription factors including peroxisome proliferator-activated receptor $(PPAR){\gamma}$, CCAT/enhancer binding protein $(C/EBP){\alpha}$ and sterol regulatory element-binding protein (SREBP-1). In addition, CSE highly increased antioxidant activity in a dose-dependent manner. CSE remarkably reduced intracellular ROS increase and NAD(P)H oxidase activity, NOX1, NOX4, Rac1 protein expression, and phosphorylation of p47phox and p67phox We also studied the effect of CSE on weight gain induced by high-fat diet. The oral treatment of CSE (500 mg/kg, body weight) in diet-induced obese (DIO) mice showed decrease in triglyceride and adipocyte size. Therefore, these results indicate that the effect of CSE on anti-obese effects, adipocyte differentiation and reducing triglyceride contents as well as adipocyte size in obese mice, may be associated with inhibition of NAD(P)H oxidase-induced ROS production and adipose transcription factors. These results showed the potential to inhibit the obesity by CSE treatment through controlling the activation of NAD(P)H oxidase in vitro and in vivo obese model.

Inhibitory Effect of KIOM-79, a New Herbal Prescription, on AGEs Formation and Expressions of Type IV Collagen and $TGF-{\beta}1$ in STZ-induced Diabetic Rats (복합한약제제 KIOM-79으I STZ 유도 당뇨 모델에서의 최종당화산물 생성 및 Type IV Collagen 및 $TGF-{\beta}1$ 발현 억제 효과)

  • Kim, Young-Sook;Lee, Yun-Mee;Kim, Chan-Sik;Sohn, Eun-Jin;Jang, Dae-Sik;Kim, Jin-Sook
    • Korean Journal of Pharmacognosy
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    • v.37 no.2 s.145
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    • pp.103-109
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    • 2006
  • Advanced glycation end products (AGEs) formation plays an important role in the progression of diabetic complications. To develop effective herbal formulations with suppression of diabetic nephropathy, a common complication in diabetic patients, we evaluated inhibitory activities of KIOM-79, a new herbal prescription, on the formation of AGEs using in vitro and in vivo model systems. Effects of KIOM-79 on the expression of AGEs, RAGEs (receptor for Advanced glycation end products), type IV collagen and renal $TGF-{\beta}1$ mRNA was also examined in streptozotocon (STZ)-induced diabetic rats. STZ-induced diabetic rats were treated orally with KIOM-79 (250 and $500\;kg^{-1}$ once a day for 13 weeks). In vitro system KIOM-79 suppressed the formation of AGEs $(18.12\;{\mu}g/ml)$. In STZ-induced diabetic rats showing accumulation of AGE and RAGE, pathological examination revealed that KIOM-79 prevented AGE and RAGE deposition in the kidney. In STZ induced diabetic rats, the expansion of mesangial matrix and the glomerular tufts seemed to be larger than those in normal rats. Howεver, after administration with KIOM-79, mesangial metrix and glomerular volume were decreased, and overexpression of type IV collagen was also decreased. Overexpression of renal $TGF-{\beta}1$ mRNA was inhibited significantly. These results suggest that the KIOM-79 might be an effective herbal prescription to prevent or alleviate the progression of diabetic nephropathy.

Attenuation of Reperfusion Injury with Angiotension $AT_1$ Receptor Blockade in Rat Myocardial Ischemic Model (백서 심근 허혈 모델에서 angiotension $AT_1$수용체 차단제의 재관류 손상 감소 효과)

  • Choi, Jun-Young;Choi, Dong-Ju;Ahn, Hyuk
    • Journal of Chest Surgery
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    • v.34 no.3
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    • pp.203-211
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    • 2001
  • 배경: AT$_1$수용체의 길항제가 세포 수준에서 심근을 재관류 손사으로부터 보호할수 있다는 것으로 알려져 있지만, 생체내에서의 효과나 그 기전은 아직 명확히 밝혀지지 않았다. 본 연구에서는 백서 심근 허혈 모델을 이용하여, AT$_1$ 수용체의 길항제들 중 하나인 irbesartan이 심근이 재관휴 손상에 미치는 효과를 알아보고, 재관류 손상을 매개하는 한 각지 기전으로서 세포자멸의 기여에 대하여 연구하고자 하였다. 대상 및 방법: Sprague-Dawley 백서에서 무작용 부형약(10% gum arabic: 1군, 개체수=14관) irbesartan(50mg/kg/day :II 군, 개체수=12)을 각각 3일 동안 24시간마다 경구로 투여하였다. 실험동물의 좌 관상 동맥을 45분간 결찰하였다가, 그 후 2시간 동안 재관류시킨 다음 심장을 적출 하였다. TTC(triphenyltetrazolium chloride) 염색법을 이용하여, 허혈 노출 부위에 대한 심근 경색 부위의 비율을 측정하였다. Agarose gel 전기영동상의 DNa 분절 양상과 TUNEL(TdT-mediated dUCP nick end labeling) 염색을 관찰하여 세포자멸이 일어난 정도를 평가하였다. 세포자멸을 조절하는데 관여하는 것으로 알려진 Bcl-2(B-cell lymphoma 2 gene), Bad 등의 단백과 ERK (extracellular signal-regulated kinase), p-38 등 신호전달체계에 작용하는 MAPKs(mitogen-activated protein kinases)의 발현을 측정하기 위하여 Western blot을 시행하였다. 결과: 허혈 노출부위에 대한 심근 경색부위의 비율은 II군(42$\pm$2.7%)이 I군( 64.1$\pm$4.65)에 비해 유의하게 작았다.(p< 0.05), Agarose gel 전기영동상의 DNA laddering 양상은 I군에서 보다 높게 발현되었다. Bad와 ERK2의 발현은 두 군간에 유의한 차이가 없었다. 결론: AT$_1$수용체 길항제인 irbesartan은 생체에서 심근의 재관류 손상을 줄이는 효과가 있었다. 이 효과는 적어도 부분적으로 나만 심근세포의 세포자멸이 감소한 것에 기인한 것으로 설명할 수 있으며, 이 항-세포 자멸 효과는 Bcl-2의 발현증가와 관련이 있는 것으로 추정되었다.

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Tumorigenic Effects of Endocrine-disrupting Chemicals are Alleviated by Licorice (Glycyrrhiza glabra) Root Extract through Suppression of AhR Expression in Mammalian Cells

  • Chu, Xiao Ting;de la Cruz, Joseph;Hwang, Seong Gu;Hong, Heeok
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.12
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    • pp.4809-4813
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    • 2014
  • Endocrine-disrupting chemicals (EDCs) have been reported to interfere with estrogen signaling. Exposure to these chemicals decreases the immune response and causes a wide range of diseases in animals and humans. Recently, many studies showed that licorice (Glycyrrhiza glabra) root extract (LRE) commonly called "gamcho" in Korea exhibits antioxidative, chemoprotective, and detoxifying properties. This study aimed to investigate the mechanism of action of LRE and to determine if and how LRE can alleviate the toxicity of EDCs. LRE was prepared by vacuum evaporation and freeze-drying after homogenization of licorice root powder that was soaked in 80% ethanol for 72 h. We used 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as a representative EDC, which is known to induce tumors or cancers; MCF-7 breast cancer cells, used as a tumor model, were treated with TCDD and various concentrations of LRE (0, 50, 100, 200, $400{\mu}g/mL$) for 24, 48, and 72 h. As a result, TCDD stimulated MCF-7 cell proliferation, but LRE significantly inhibited TCDD-induced MCF-7 cell proliferation in a dose- and time-dependent manner. The expression of TCDD toxicity-related genes, i.e., aryl hydrocarbon receptor (AhR), AhR nuclear translocator, and cytochrome P450 1A1, was also down-regulated by LRE in a dose-dependent manner. Analysis of cell cycle distribution after treatment of MCF-7 cells with TCDD showed that LRE inhibited the proliferation of MCF-7 cells via G2/M phase arrest. Reverse transcription-polymerase chain reaction and Western blot analysis also revealed that LRE dose-dependently increased the expression of the tumor suppressor genes p53 and p27 and down-regulated the expression of cell cycle-related genes. These data suggest that LRE can mitigate the tumorigenic effects of TCDD in breast cancer cells by suppression of AhR expression and cell cycle arrest. Thus, LRE can be used as a potential toxicity-alleviating agent against EDC-mediated diseases.

D-Amphetamine Causes Dual Actions on Catecholamine Release from the Rat Adrenal Medulla

  • Lim, Geon-Han;Na, Gwang-Moon;Min, Seon-Young;Seo, Yoo-Seok;Park, Chan-Won;Lim, Dong-Yoon
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.1
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    • pp.45-53
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    • 2005
  • The present study was designed to examine the effect of d-amphetamine on CA release from the isolated perfused model of the rat adrenal gland, and to establish its mechanism of action. Damphetamine $(10{\sim}100{\mu}M$), when perfused into an adrenal vein of the rat adrenal gland for 60 min, enhanced the CA secretory responses evoked by ACh ($5.32{\times}10^{-3}$ M), excess $K^+$ ($5.6{\times}10^{-2}$ M, a membrane depolarizer), DMPP ($10^{-4}$ M, a selective neuronal nicotinic $N_n-receptor$ agonist) and McN-A-343 ($10^{-4}$ M, a selective $M_1-muscarinic$ agonist) only for the first period (4 min), although it alone has weak effect on CA secretion. Moreover, d-amphetamine ($30{\mu}M$) in to an adrenal vein for 60 min also augmented the CA release evoked by BAY-K-8644, an activator of the dihydropyridine L-type $Ca^{2+}$ channels, and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}$ ATPase only for the first period (4 min). However, in the presence of high concentration ($500{\mu}M$), d-amphetamine rather inhibited the CA secretory responses evoked by the above all of secretagogues. Collectively, these experimental results suggest that d-amphetamine at low concentrations enhances the CA secretion from the rat adrenal medulla evoked by cholinergic stimulation (both nicotininc and muscarinic receptors) as well as by membrane depolarization, but at high concentration it rather inhibits them. It seems that d-amphetamine has dual effects as both agonist and antagonist at nicotinic receptors of the isolated perfused rat adrenal medulla, which might be dependent on the concentration. It is also thought that these actions of d-amphetamine are probably relevant to the $Ca^{2+}$ mobilization through the dihydropyridine L-type $Ca^{2+}$ cha$N_n$els located on the rat adrenomedullary chromaffin cell membrane and the release of $Ca^{2+}$ from the cytoplasmic store.

Changes in Steroid Receptor Number of and Bioactivity of Gonadotropin in the Follicular Fluid of Porcine Ovafian Atretic Follicles I. Bioavailable Testosterone (돼지의 폐쇄여포내 스테로이드 수용체의 변화와 여포액내 생식소자극 호르몬의 활성도 변화 1. 활성적 Testosterone의 농도)

  • 윤용달;이창주;전은현;이주영
    • The Korean Journal of Zoology
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    • v.32 no.3
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    • pp.281-289
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    • 1989
  • The present study was disigned to determine the concentration of bioavailable steroid hormones in the atretic follicular fluid (FF). The concentradons of progesterone (P), testosterone (T), estradiol (E), androstenedione (A), and 5-$\alpha$ dihydrotestosterone (DIlT) were determined by the established methods of luminescent immunoassay (LIA) or radioimmunoassay (RIA). Concentrations of T, A and Diff in human FF from smail (< 6 mm). medium (8-15 mm), and large (> 15 mm) atretic follicles were significandy higher than those of normal ones (p < 0.01). However, the levels of T, A and DHT in smail atretic foflicle were significandy lower than those found in normal one. The concentrations of P in atretic FF from porcine small (< 3 mm), medium (4-6 mm), and large (> 7 mm) follicles were not different from that of normal ones. However, the concentration of E in atretic forncles of each group was significantly lower than that of normal group (p < 0.001 in each group). On the other hand, the percentages of bioavailable T (BI) in human FF were significandy (p <0.001) higher than those in normal groups. The BT in normal or atretic FF was more than 90 % of total T. The present result demonstrates that the bioavailable androgen, but not E levels in atretic follicles is higher than that of normal one, and that the atretic mechanism might be dependent on the ovarian forncle size in the developmental stage and on the animal model system. Moreover, the present study suggests that the steroids found in the FF are the bioavailable forms and the concentration of BT in FF could be used as one of the valuable criteria classifying the ovarian atretic follicle.

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PLEIOTROPHIN EFFECTS ON BINDING AND SUBSEQUENT OSTEOGENESIS OF HUMAN MESENCHYMAL STEM CELLS (Pleiotrophin이 골수 줄기 세포의 부착 및 골형성에 미치는 효과에 대한 연구)

  • Yoon, Jung-Ho;Eune, Jung-Ju;Jang, Hyon-Seok;Rim, Jae-Suk;Lee, Eui-Seok;Kim, Dae-Sung;Kwon, Jong-Jin
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.28 no.2
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    • pp.111-117
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    • 2006
  • An area of current research is investigating the app1ication of human mesenchymal stem cells or hMSCs as a cell-based regenerative therapy. In order to achieve effective bone regeneration, appropriate matrices functioning as cell-carriers must be identified and optimized in terms of function, efficacy and biocompatibility. Two methods of approaching optimization of matrices are to facilitate adhesion of the donor hMSCs and furthermore to facilitate recruitment of host progenitor cells to osteoblastic differentiation. Pleiotrophin is an extracellular matrix protein that was first identified in developing rat brains and believed to be associated with developing neuronal pathways. A recent publication by Imai and colleagues demonstrated that transgenic mice with upregulated pleiotrophin expression developed a greater volume of cortical as well as cancellous bone. The proposed mechanism of action of pleiotrophin is demonstrated here. Through either environmental stresses and/or intracellular regulation, there is an increase in pleiotrophin production. The pleiotrophin is released extracellularly into areas requiring bone deposition. A receptor-mediated process recruits host osteoprogenitor cells into these areas. Therefore, the aim of our study was to investigate the osteoconductive properties of pleiotrophin. We wanted to determine if pleiotrophin coating facilitates cellular adhesion and furthermore if this has any effect on hMSCs derived bone formation in an animal model. The results showed a dose dependent response of cellular adhesion in fibronectin samples, and cellular adhesion was facilitated with increasing pleiotrophin concentrations. Histologic findings taken after 5 weeks implantation in SCID mouse showed no presence of bone formation with only a dense fibrous connective tissue. Possible explanations for the results of the osteogenesis assay include inappropriate cell loading.

Study on the Influenza Type A Activity of Fractions of Korean Medicinal Herbs (한약 단미제 분획의 Influenza virus type A 활성에 관한연구)

  • Jung, Jae-Deuk;Park, In-Ho;Lee, Kwang-Hee;Kim, Ho-Kyoung;Ko, Byung-Seob;Park, Kap-Joo
    • Korean Journal of Oriental Medicine
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    • v.3 no.1
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    • pp.67-83
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    • 1997
  • In order to search for anti-influenza virus type A agents from Korean medicinal herbs, we selected 100 medicinal herbs, based on a review of the Korean traditional medicine books. Four of 100 Korean medicinal herbs, MM-40, MM-55, MM-63, MM-110, exhibited very strong anti-influenza virus activity. The fractions of four medicinal herbs, which had very strong anti-influenza virus activity, were tested for antiviral activity by means of Haemagglutination inhibition test(HTT), 40% MeOH fraction of MM-40, $H_2O$ fraction of MM-55, 20% fraction of MM-63 3nd $H_2O$ fraction of MM-110 had strong anti-influenza virus activity at the range of $78{\mu}g/ml$ to $156{\mu}g/ml$, 1.56mg/ml to 100mg/ml, 6.25mg/ml to 50mg/ml and $48.7{\mu}g/ml$ to $780{\mu}g/ml$, respectively. These results of HIT indicated that fractions of Korean medicinal herbs might inhibit either attachment of virus to cell surface receptor or penetration of virus into cell during the initial stage of infection. In the cytotoxicity of fractions against red blood cells, 40% MeOH fraction of MM-40, 20% fraction of MM-63 and $H_2O$ fraction of MM-110 showed cytotoxicity at the range of $78{\mu}g/ml$ to 10mg/ml, 50mg/ml to 100mg/ml and $195{\mu}g/ml$ to 100mg/ml, respectively, whereas $H_2O$ fraction of MM-55 did not show cytotoxicity. In order to establish influenza virus adapted animal model, influenza virus type A were passaged 3 and 4 times successively in Balb/c mouse. As a result, we had 4 HA unit titers on the 5 days of 3rd passages and 7 days of 4th passages after infection, respectively.

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Histone H3 Lysine Methylation in Adipogenesis (Adipogenesis에서 히스톤 H3 lysine methylation)

  • Jang, Younghoon
    • Journal of Life Science
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    • v.30 no.8
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    • pp.713-721
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    • 2020
  • Adipogenesis as a model system is needed to understand the molecular mechanisms of human adipocyte biology and the pathogenesis of obesity, diabetes, and other metabolic syndromes. Many relevant studies have been conducted with a focus on gene expression regulation and intracellular signaling relating to Peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein alpha (C/EBPα), which are master adipogenic transcription factors. However, epigenome regulation of adipogenesis by epigenomic modifiers or histone mutations is not fully understood. Histone methylation is one of the major epigenetic modifications on gene expression in mammals, and histone H3 lysine methylation (H3Kme) in particular implicates cell differentiation during various tissue and organ development. During adipogenesis, cell type-specific enhancers are marked by histone H3K4me1 with the active enhancer mark H3K27ac. Mixed-lineage leukemia 4 (MLL4) is a major H3K4 mono-methyltransferase on the adipogenic enhancers of PPARγ and C/EBPα loci. Thus, MLL4 is an important epigenomic modifier for adipogenesis. The repressive mark H3K27me3 is mediated by the enzymatic subunit Enhancer zeste homolog 2 (EZH2) of the polycomb repressive complex 2. EZH2-mediated H3K27 tri-methylation on the Wnt gene increases adipogenesis because WNT signaling is a negative regulator of adipogenesis. This review summarizes current knowledge about the epigenomic regulation of adipogenesis by histone H3 lysine methylation which fundamentally regulates gene expression.

The Mechanism for Analgesic Effects of Electroacupuncture on Surgical Ankle Sprain Model Classified as Grade 3 in Rats (수술적 방법으로 유도된 3단계 발목염좌에 대한 전침의 진통기전 연구)

  • Yang, Seung-Bum;Choi, Suck-Jun;Lee, Sung-Ho;Kim, Min-Su;Sohn, In-Chul;Kim, Jae-Hyo
    • Korean Journal of Acupuncture
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    • v.30 no.4
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    • pp.220-229
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    • 2013
  • Objectives : Electroacupuncture(EA) has been used effectively in producing analgesia on ankle sprain pain of humans and animals. Currently to examine the underlying mechanisms of the EA-induced analgesia, the effects of EA on weight-bearing forces(WBR) were examined at ankle sprain classified as grade 3 in rats. Methods : The severe ankle sprain classified as grade 3 was induced surgically by ankle ligament injury in the Sprague-Dawley rats. WBR of the affected foot were examined to evaluate effects and mechanism of EA(2 Hz, 1 ms pulse width, 2 mA intensity, for 15 min) which was applied to either SI6, GB34, or GB39 acupoints. The rats were pretreated with naltrexone(10 mg/kg, i.p.) as an opioid receptor antagonist or phentolamine(5 mg/kg, i.p) as an ${\alpha}$-adrenoceptor antagonist at 30 min before EA. Results : The daily repeat EA at either SI6, GB34, or GB39 showed significant analgesic effects on the severe ankle sprain. Particularly, daily EA at GB34 showed more potent analgesic effect than the others. In addition, the naltrexone pretreatment completely blocked the analgesic effect of EA at GB34, indicating the involvement of the endogenous opioid system in mediating the effect of EA at GB34. However, the phentolamine pretreament blocked analgesic effects of EA at either SI6 or GB39, indicating the involvement of ${\alpha}$-adrenoceptors in mediating the effect of EA at either SI6 or GB39. Conclusions : These data suggest that EA-induced analgesia on ankle sprain pain is mediated through either endogenous opioids or ${\alpha}$-adrenoceptors dependant on acupoint specific pattern.