• 산업융합연구
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• 제21권10호
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• pp.57-63
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• 2023

평활근 수축에 대한 감초산(glycyrrhizic acid)의 효과를 연구하고자 하였고 관련 상세 기전을 결정하기 위해 glycyrrhizic acid가 agonist-sensitive하게 평활근 수축한다는 가설을 제시하였다. S/D rats의 평활근을 수조 내 준비하였고 신호 변환기에서 평활근에 의한 운동 신호가 전기적 신호로 변환되어 생리기록기에 표시되는 데이터는 일원배치 분산분석으로 분석하였다. 재미있게도, 감초산은 불화물, 트롬복산 유사체 등 굵은 미세섬유성 조절성 수축제에 의한 평활근 수축을 중등도로 억제하였고 (농도 0.01, 0.03, 0.1 mM 불화물에서 p=0.113, 0.008, 0.004 (Student's t-test), p=0.113, 0.008, 0.004 (One way ANOVA), 그리고 0.01, 0.03, 0.1 mM 트롬복산 유사체에서 p=0.156, 0.004, 0.003 (Student's t-test), p=0.156, 0.004, 0.003 (One way ANOVA)) 포볼 에스테르 등 가는 미세섬유성 조절성 수축제에 의한 평활근 수축에 대해 효과가 소실되었다 (0.01, 0.03, 0.1 mM 포볼 에스테르에서 p=0.392, 0.086, 0.065 (Student's t-test), p=0.392, 0.086, 0.065 (One way ANOVA)). 이러한 결과는 내피 기능이 억제된 평활근에서 감초산은 평활근 내피에서 EDRF (NO) 생성 효과 외에 주로 ROCK 활성 감소 등 평활근에 대한 직접적 효과를 통해 최종적으로 평활근에서 악틴-미오신 상호작용을 제한하여 평활근을 이완시키는 것으로 생각된다.

• 약학회지
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• 제57권5호
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• pp.376-381
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• 2013

The present study was undertaken to investigate the influence of curcumin on vascular smooth muscle contractility and to determine the mechanism involved. We hypothesized that curcumin, the primary ingredient of Curcuma longa, plays a role in vascular relaxation through inhibition of Rho-kinase in rat aortae. Denuded arterial rings from male Sprague-Dawley rats were used and isometric tensions were recorded using a computerized data acquisition system. Interestingly, curcumin inhibited fluoride-induced contraction but didn't inhibit phorbol ester-induced contraction suggesting that additional pathways different from endothelial nitric oxide synthesis might be involved in the vasorelaxation. Furthermore, curcumin significantly inhibited fluoride-induced increases in pMYPT1 levels. On the other hand, it didn't significantly inhibit phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving inhibition of fluoride-induced MYPT1 phosphorylation. This study provides evidence that curcumin induces vascular relaxation through inhibition of Rho-kinase in rat aortae.

• 한국안전학회지
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• 제15권1호
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• pp.153-160
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• 2000

Occupational cumulative traumas (CTDs) are becoming one of leading ailments in industrialized worl $d^{(1.2)}$. The degree of muscle fatigue is important parameter to understand cause of occupational cumulative trauma disorders. To quantify degree of muscle fatigue, muscle EMG activity was measured during isometric and dynamic contractions(repetitive concentric/eccentric muscle contraction) and its analyzed data, such as RMS, median frequency, and median power were compared when the muscle was fresh and exhausted. When muscle become fatigue, it was observed that median frequency decreased and median power and RMS increased However, based on overall prolonged observation, median frequency increased and median power and RMS decreased. Therefore it was concluded that shifting patterns of RMS, median frequency, and median power values can be used as parameter to evaluate degree of muscle fatigue even in dynamic muscle contraction.

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.69-74
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• 2016

The present study was undertaken to investigate the influence of cardamonin on vascular smooth muscle contractility and to determine the mechanism(s) involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Cardamonin significantly relaxed fluoride-, phenylephrine-, and phorbol ester-induced vascular contractions, suggesting that it has an anti-hypertensive effect on agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, cardamonin significantly inhibited the fluoride-induced increase in pMYPT1 level and phenylephrine-induced increase in pERK1/2 level, suggesting inhibition of Rho-kinase and MEK activity and subsequent phosphorylation of MYPT1 and ERK1/2. This study provides evidence that the relaxing effect of cardamonin on agonist-induced vascular contraction regardless of endothelial function involves inhibition of Rho-kinase and MEK activity.

• 약학회지
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• 제58권5호
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• pp.337-342
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• 2014

The present study was undertaken to investigate the influence of diosgenin on vascular smooth muscle contractility and to determine the mechanism involved. We hypothesized that diosgenin, the primary ingredient of Dioscorea villosa, plays a role in vascular relaxation through inhibition of Rho-kinase in rat aortae. Denuded arterial rings from male Sprague-Dawley rats were used and isometric tensions were recorded using a computerized data acquisition system. Interestingly, diosgenin inhibited fluoride-induced contraction but didn't inhibit phorbol ester-induced contraction suggesting that additional pathways different from endothelial nitric oxide synthesis such as inhibition of Rho-kinase might be involved in the vasorelaxation. Furthermore, diosgenin didn't inhibit thromboxane $A_2$-induced increases in pERK1/2 levels suggesting the mechanism excluding inhibition of thromboxane $A_2$-induced increases in ERK1/2 phosphorylation. This study provides evidence that diosgenin induces vascular relaxation through inhibition of Rho-kinase in rat aortae.

• The Korean Journal of Physiology
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• 제27권1호
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• pp.27-35
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• 1993

Effects of the endothelium on the contractile responses to norepinephrine (NE) were investigated in isolated helical strips of the proximal and distal coronaries artery of pigs. The helical strips were immersed in Tris-buffered Tyrode's solution equilibrated with 100% $O_2$ at $35^{\circ}C$ and its isometric tension was measured. NE relaxed the strips precontracted with acetylcholine from both the proximal and distal coronary artery. NE-induced relaxation, which might be induced mainly by $\beta$-adrenoceptor function was dominant in the distal coronary arteries. NE-induced relaxation was converted to a contraction after $\beta$-adrenoceptor blockade with propranolol $(3{\times}10^{-6}M)$. ${\alpha}$-adrenoceptor-mediated contraction by NE was greater in the proximal coronary artery than the distal coronary artery. Quantitatively, ${\alpha}_1$-adrenoceptor mediated contraction by NE was greater than ${\alpha}_2$-adrenoceptor mediated contraction by NE in both arteries. NE-induced relaxation was decreased by rubbing of endothelium in both arteries. ${\alpha}_1-and\;{\alpha}_2$-adrenoceptor mediated contraction by NE were potentiated by rubbing of endothelium in both arteries. Pretreatment with methylene blue, an inhibitor of soluble guanylate cyclase, increased ${\alpha}_1-\;and\;{\alpha}_2$-adrenoceptor mediated contraction by NE in both arteries with endothelium. From the above results, we suggest that the effect of activation of $\alpha$-adrenoceptors by NE may be modulated by endothelium in the proximal and distal coronary arteries of pigs. This effect may be mediated via endothelium derived relaxing factor.

• The Korean Journal of Physiology
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• 제29권2호
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• pp.233-241
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• 1995

The nonapeptide bradykinin has been shown to exhibit an array of biological activities including relaxation/contraction of various smooth muscles. In order to investigate the effects of bradykinin on the contractility and the electrical activity of antral circular muscle of guinea-pig stomach, the isometric contraction and membrane potential were recorded. Also, using standard patch clamp technique, the $Ca^{2+}-activated$ K currents were recorded to observe the change in cytosolic $Ca^{2+}$ concentration. $0.4 {\mu}M$ bradykinin induced a triphasic contractile response (transient contraction-transient relaxation-sustained contraction) and this response was unaffected by pretreatment with neural blockers (tetrodotoxin, atropine and guanethidine) or with apamin. Bradykinin induced hyperpolarization of resting membrane potential and enhanced the amplitude of slow waves and spike potentials. The enhancement of spike potentials was blocked by neural blockers. Both the bradykinin-induced contractions and changes in membrane potential were reversed by the selective $B_2$-receptor antagonist $(N{\alpha}-adamantaneacetyl-_{D}-Arg-[Hyp, Thy,_{D}-Phe]-bradykinin)$. In whole-cell patch clamp experiment, we held the membrane potential at -20 mV and spontaneous and transient changes of Ca-activated K currents were recorded. Bradykinin induced a large transient outward current, consistent with a calcium-releasing action of bradykinin front the intracellular calcium pool, because such change was blocked by pretreatment with caffeine. Bradykinin-induced contraction was also blocked by pretreatment with caffeine. From these results, it is suggested that bradykinin induces a calciumrelease and contraction through the $B_{2}$ receptor of guinea-pig gastric smooth muscle. Enhancement of slow wave activity is an indirect action of bradykinin through enteric nerve cells embedded in muscle strip.

• 융합정보논문지
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• 제11권10호
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• pp.131-137
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• 2021

본 연구에서 진단, 과민반응 검사에 사용되며 의약품에 불순물로 포함되어 규제되는 histamine의 단독 및 병용 투여에서 조직/근육 선택적 장관 수축성 조절에 대한 실험을 하고자 하였다. Histamine은 muscarinic receptor 작용 외에 histamine H1 receptor에 대한 직접 작용으로 수축성을 증가시켰고 회장/결장 윤주근에서 수축성을 거의 증가시키지 않았다. 또한 M3 수용체에 선택적으로 작용하는 atropine의 병용 효과를 관찰하였는데 histamine과 병용된 atropine은 장관 중 회장의 종주근의 수축성을 거의 감소시키지 않았고 회장/결장의 윤주근의 수축성을 감소시키지 않았다. 따라서 적어도 회장의 종주근에서 histamine은 M3 수용체를 거의 경유하지 않고 작용하고 atropine은 항무스카린 효과 외에 histamine에 의한 조직 선택적 위장관 운동성을 거의 조절하지 않는 것으로 생각된다. 그리고 이러한 단순한 검색은 의약품 불순물 검사로 선호될 것으로 생각된다.

• 한국운동역학회지
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• 제21권3호
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• pp.297-308
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• 2011

The purpose of this study was to investigate the relationship among isometric and isokinetic muscle strength, lean body mass(LBM) and bone mineral density(BMD) in the elderly. Eleven males(age, 70.27${\pm}$5.78yr; height, 167.36${\pm}$6.68 cm; weight, 68.34${\pm}$8.23 kg) and thirteen female(age, 69.77${\pm}$4.13yr; height, 152.80${\pm}$4.45 cm; weight, 56.86${\pm}$7.40 kg) participated in this study. In all subjects, LBM and BMD segments was measured by using Dual-energy x-ray absorptiometry(DEXA, Lunar DPS-DM, U.S.A.). Maximum isometric and isokinetic muscle strength of flexion and extension at the knee and elbow, ankle, trunk joints were measured by using an isokinetic dynamometer(CON-TREX(R) Multi Joint Testing Module, Switzerland). The results of this study showed that isometric and isokinetic muscle strength was significantly higher in extension than flexion. In the male and female, hamstring to quadriceps strength ratio(H:Q ratio) was increased as contraction velocity increased. BMD was correlated significantly with trunk extension in the male, but not in the female. LBM was correlated significantly in the male and female with knee extension strength. This study suggests that in the elderly muscle strength training program should put more weight on extensor muscles of the body.

• 대한물리치료과학회지
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• 제9권3호
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• pp.77-87
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• 2002

The purpose of this study was to compare the changes of muscle activities in deltoid with those in supraspinatus using electromyography(EMG) while subjects abducted their shoulder to different angles with different resistance. Methods : 20 volunteers who were comprised of 10 males(mean age: $21.2{\pm}2.0$) and 10 females(mean age: $20.2{\pm}1.6$) were collected. Surface electrodes were attached on deltoid and supraspinatus muscle for recording. Each reference electrode was located 3 cm to the each recording electrode. Muscle action potentials were recorded with changing the angle of shoulder abduction, $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. This procedure was repeated with different resistance 0 pound, 2 pounds, 4.5pounds. The angle of shoulder abduction was determined by clinical goniometer. SPSS(Statistical Program for Social Science)/WIN 10.0 was used for statistics. Analysis included ANOVA, T-test. Results : The following results were obtained in this study. 1. There was significant differences during isometric shoulder abduction $30^{\circ}$, $60^{\circ}$, $90^{\circ}$ comparing muscle activity in deltoid and supraspinatus muscles at 0 pound, 2pound, 4.5pound resistance(p<0.05). 2. There was no useful significant in the deltoid and supraspinatus muscles activity EMG compared by physical condition. 3. Their was significant in the deltoid EMG compared by gender t=-5.41, P<0.01, but no difference in the supraspinatus EMG(P=0.333 >a=0.05). Conclusions: There are many previous studies on influence of shoulder angles and speeds of muscle activity. However most of them placed the focus on isotonic or isokinetic exercise, or shoulder function. But this study was done during isometric exercise, which is better for early assessment and treatment for injured patients. There is strong relationship between the shoulder angle with resistance in deltoid supraspinatus muscle activity. We conclude that it is important to apply isometric shoulder abduction exercise with correct angle and resistance especially in early stage.