• The Korean Journal of Physiology and Pharmacology
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• 제21권1호
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• pp.1-9
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• 2017

Intestinal disorders often co-occur with inflammation and dysmotility. However, drugs which simultaneously improve intestinal inflammation and co-occurring dysmotility are rarely reported. Atractylodin, a widely used herbal medicine, is used to treat digestive disorders. The present study was designed to characterize the effects of atractylodin on amelioration of both jejunal inflammation and the co-occurring dysmotility in both constipation-prominent (CP) and diarrhea-prominent (DP) rats. The results indicated that atractylodin reduced proinflammatory cytokines TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 in the plasma and inhibited the expression of inflammatory mediators iNOS and NF-kappa B in jejunal segments in both CP and DP rats. The results indicated that atractylodin exerted stimulatory effects and inhibitory effects on the contractility of jejunal segments isolated from CP and DP rats respectively, showing a contractile-state-dependent regulation. Atractylodin-induced contractile-state-dependent regulation was also observed by using rat jejunal segments in low and high contractile states respectively (5 pairs of low/high contractile states). Atractylodin up-regulated the decreased phosphorylation of 20 kDa myosin light chain, protein contents of myosin light chain kinase (MLCK), and MLCK mRNA expression in jejunal segments of CP rats and down-regulated those increased parameters in DP rats. Taken together, atractylodin alleviated rat jejunal inflammation and exerted contractile-state-dependent regulation on the contractility of jejunal segments isolated from CP and DP rats respectively, suggesting the potential clinical implication for ameliorating intestinal inflammation and co-occurring dysmotility.

• Biomolecules & Therapeutics
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• 제19권4호
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• pp.477-486
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• 2011

The purpose of the present study was to investigate whether polyphenol-rich fraction extracted from fruit wine of Rubus coreanum M (PCRC) can affect the contractility of the thoacic aortic strips isolated from spontaneously hypertensive rats (SHRs), and to clarify its mechanism of action. PCRC (200-800 ${\mu}g/mL$) concentration-depenedently blocked phenylephrine (10 ${\mu}M$)-induced contractile responses of the isolated aortic strips of SHRs. PCRC (400 ${\mu}g/mL$), added in to bath medium, also depressed the contractile active tension evoked by both phenylephrine (3 and 10 ${\mu}M$) and high potassium (25 and 56 mM). In the simultaneous presence of PCRC (400 ${\mu}g/mL$) and L-NAME (a selective inhibitor of NO synthase, 300 ${\mu}M$), the contractile responses evoked by phenylephrine and high $K^+$ were recovered to considerable level of the corresponding control contractility compared with those effects of PCRC-treatment alone. However, in the simultaneous presence of indomethacin (10 ${\mu}M$, a selective cyclooxygenase inhibitor) and PCRC (400 ${\mu}g/mL$), they were not affected. In the endothelium-denuded aortic strips by CHAPS-treatment, PCRC did not affect the contractile responses induced by phenylephrine or high potassium. Interestingly, PCRC (1.0, 3.0 and 10.0 mg/kg/30 min, i.v., respectively) dose-dependently suppressed norepiphrine-induced vasopressor responses in anesthetized SHRs. Collectively, we concluded that PCRC causes vasorelaxation in the thoracic aortic strips with intact endothelium of SHRs at least partly by the increased NO production through the activation of NO synthase of vascular endothelium, but not through the activation of cyclooxygenase. These results suggest that PCRC might be helpful to prevent or alleviate cardiovascular diseases, including hypertension.

• Biomolecules & Therapeutics
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• 제27권1호
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• pp.101-106
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• 2019

Most diabetic patients experience diabetic mellitus (DM) urinary bladder dysfunction. A number of studies evaluate bladder smooth muscle contraction in DM. In this study, we evaluated the change of bladder smooth muscle contraction between normal rats and DM rats. Furthermore, we used pharmacological inhibitors to determine the differences in the signaling pathways between normal and DM rats. Rats in the DM group received an intraperitoneal injection of 65 mg/kg streptozotocin and measured blood glucose level after 14 days to confirm DM. Bladder smooth muscle contraction was induced using acetylcholine (ACh, $10^{-4}M$). The materials such as, atropine (a muscarinic receptor antagonist), U73122 (a phospholipase C inhibitor), DPCPX (an adenosine $A_1$ receptor antagonist), udenafil (a PDE5 inhibitor), prazosin (an ${\alpha}_1$-receptor antagonist), papaverine (a smooth muscle relaxant), verapamil (a calcium channel blocker), and chelerythrine (a protein kinase C inhibitor) were pre-treated in bladder smooth muscle. We found that the DM rats had lower bladder smooth muscle contractility than normal rats. When prazosin, udenafil, verapamil, and U73122 were pre-treated, there were significant differences between normal and DM rats. Taken together, it was concluded that the change of intracellular $Ca^{2+}$ release mediated by PLC/IP3 and PDE5 activity were responsible for decreased bladder smooth muscle contractility in DM rats.

• The Korean Journal of Physiology and Pharmacology
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• 제1권6호
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• pp.769-774
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• 1997

Non-neuronal high affinity binding sites for benzodiazepines have been found in many peripheral tissues including cardiac muscle and vascular smooth muscle, and have been designated as 'peripheral benzodiazepine receptor'. Benzodiazepines have been shown to induce relaxation of the ileal, vesical, and uterine smooth muscles. However, it is still unclear about possible involvement of peripheral benzodiazepine receptor on the contractility of trachealis muscle. This study was performed to investigate the role of the peripheral benzodiazepine receptor on the contractility of canine trachealis muscle. Canine trachealis muscle strips of 15 mm long were suspended in an isolated organ bath containing 1 ml of physiological salt solution maintained at $37^{\circ}C$, and aerated with $95%\;O_2/5%\;CO_2$. Isometric myography was performed, and the results of the experiments were as follows: Ro5-4684, FGIN-1-27 and clonazepam reduced a basal tone of isolated canine trachealis muscle strip concentration dependently, relaxant actions of RoS-4684 and FGIN-1-27 were antagonized by PK11195, a peripheral benzodiazepine receptor antagonist. Flumazenil, a central type antagonist, did not antagonize the relaxant action of Peripheral type agonists. Saturation binding assay of [3H]Ro5-4864 showed a high affinity$(Kd=5.33{\pm}1.27nM,\;Bmax=\;867.3{\pm}147.2\;fmol/mg\;protein)$ binding site on the canine trachealis muscle. Ro 5-4684 suppressed the bethanechol-, 5-hydroxyoyptamine- and histamine- induced contractions. Platelet activating factor (PAF) exerted strong and prolonged contraction in trachealis muscle strip. Strong tonic contraction by PAE was attenuated by Ro 5-4684, but not by WEB 2086, a PAF antagonist. Based on these results, it is concluded that the peripheral benzodiazepine receptor mediates the inhibitory regulation of contractilty of canine trachealis muscle.

• 생명과학회지
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• 제24권10호
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• pp.1125-1131
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• 2014

본 연구는 65세 이상의 비만노인과 일반노인의 대퇴부 근육량과 등속성 근력을 비교하기 위해 수행되었다. 본 연구의 피험자는 65~79세 사이 노인들을 비만군(BMI>25, N=21)과 일반군(BMI<25, N=13)으로 구성하였다. 본 연구의 목적을 달성하기 위해 대퇴부 근육량 및 지방량 측정 등은 CT 촬영을 통해 측정하였고, 대퇴부 등속성 근력은 BIODEX를 이용해 최대 신전력을 측정하였다. 모든 변인은 two-way ANOVA로 검증한 후 유의한 경우 Contrast test를 통해 사후분석을 실시하였다. 그 결과 대퇴부 총 부피는 남녀 모두 그룹간 유의한 차이가 나타났다. 대퇴부 근육 부피는 비만군 남자가 일반군 남자보다 유의하게 높게 나타났으며 비만군에서 남녀 성별간 유의한 차이를 보였다. 피하지방은 그룹간과 그룹내 성별간 유의한 차이가 나타났으며, 근간지방의 경우 비만군과 일반군의 동일 성별간에서만 유의한 차이가 나타났다. 또한 근간지방은 일반군 남자에서 비만인 남자에 비해 유의하게 높게 나타났으며 성별간 유의한 차이도 확인되었다. 이상의 연구 결과를 종합해보면 비만 노인은 일반노인보다 남녀 모두 큰 대퇴부 근육 부피를 가지고 있음에도 불구하고, 단위 체중당 대퇴부 근력은 일반노인이 높은 것으로 나타났다. 이는 비만노인에 비해 일반노인의 근육기능이 생리적으로 더 우수하다는 것을 의미한다.

• 대한약리학회지
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• 제31권3호
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• pp.279-284
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• 1995

본 연구의 목적은 외부에서 nitric oxide (NO)를 투여 하였을때 심근 수축력, 심박동수의 변화 및 혈관 평활근에 대한 효과를 비교함으로서 NO에 대한 이들 장기의 민감도가 서로 같은지 또는 상이한지를 알아보고자 하였다. 본 실험에서는 PIANO 방법에 의한 근장력의 변화와 아울러 심근에서의 $Ca^{2+}$ current를 측정하였다. 랫트의 심방근에 대한 PIANO $(STZ,\;100\;{\mu}M)$는 심근수축력 및 심박동수에 전혀 변화를 주지 않았지만 혈관 평활근에서는 강한 이완 작용을 나타내었다. 한편, 8-Br-cGMP도 고농도 $(100\;{\mu}M)$에서만 심근 수축력을 억제하였다. 토끼의 심방근세포에서 Whole cell voltage patch clamp를 사용시 bradykinin, SNP, 8-Br-cGMP 및 PIANO는 $Ca^{2+}$ current를 억제하였다. 이러한 사실은 외부에서 공급되는 NO에 대한 심근과 혈관 평활근의 반응에는 민감도의 차이가 있음을 암시하며 더 나아가 심근의 경우에도 NO 반응에는 종 (species)간의 차이와 동일 종이라 하더라도 세포(cell)와 장기(tissue)에 차이가 있을 가능성을 제시하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제17권4호
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• pp.359-365
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• 2013

Plasma pH can be altered during pregnancy and at labor. Membrane excitability of smooth muscle including uterine muscle is suppressed by the activation of $K^+$ channels. Because contractility of uterine muscle is regulated by extracellular pH and humoral factors, $K^+$ conductance could be connected to factors regulating uterine contractility during pregnancy. Here, we showed that TASK-2 inhibitors such as quinidine, lidocaine, and extracellular acidosis produced contraction in uterine circular muscle of mouse. Furthermore, contractility was significantly increased in pregnant uterine circular muscle than that of non-pregnant muscle. These patterns were not changed even in the presence of tetraetylammonium (TEA) and 4-aminopyridine (4-AP). Finally, TASK-2 inhibitors induced strong myometrial contraction even in the presence of L-methionine, a known inhibitor of stretch-activated channels in myometrium. When compared to non-pregnant myometrium, pregnant myometrium showed increased immunohistochemical expression of TASK-2. Therefore, TASK-2, seems to play a key role during regulation of myometrial contractility in the pregnancy and provides new insight into preventing preterm delivery.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.43-43
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• 2003

Viable myocardium can be distinguished from the infarcted myocardium by contrast-enhanced magnetic resonance imaging (ceMRI). In this study, contrast-enhancement with cine magnetic resonance imaging (cecineMRI) was performed for direct correlation of transmural extent of hyperenhancement and that of contractility.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.89-90
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• 2003

Viable myocardium can be distinguished from the infarcted myocardium by contrast-enhanced magnetic resonance imaging (ceMRI). In this study, contrast-enhancement with cine magnetic resonance imaging (cecineMRI) was performed for direct correlation of transmural extent of hyperenhancement and that of contractility.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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• pp.17-17
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• 2001

It is well known that myocardial stretch causes changes in electrical signalling and contractility of the heart. For example, mechanical stretch depolarises the membrane potential of cardiac cells and alters the shape of action potentials. As a result, these effects either accelerate the frequency of heart rate or induce arrhythmias of the heart.(omitted)