• The Korean Journal of Physiology and Pharmacology
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• 제22권5호
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• pp.577-584
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• 2018

Bladder dysfunction is a common complication of diabetes mellitus (DM). However, there have been a few studies evaluating bladder smooth muscle contraction in DM in the presence of pharmacological inhibitors. In the present study, we compared the contractility of bladder smooth muscle from normal rats and DM rats. Furthermore, we utilized pharmacological inhibitors to delineate the mechanisms underlying bladder muscle differences between normal and DM rats. DM was established in 14 days after using a single injection of streptozotocin (65 mg/kg, intraperitoneal) in Sprague-Dawley rats. Bladder smooth muscle contraction was induced electrically using electrical field stimulation consisting of pulse trains at an amplitude of 40 V and pulse duration of 1 ms at frequencies of 2-10 Hz. In this study, the pharmacological inhibitors atropine (muscarinic receptor antagonist), U73122 (phospholipase C inhibitor), DPCPX (adenosine $A_1$ receptor antagonist), udenafil (PDE5 inhibitor), prazosin (${\alpha}_1$-receptor antagonist), verapamil (calcium channel blocker), and chelerythrine (protein kinase C inhibitor) were used to pretreat bladder smooth muscles. It was found that the contractility of bladder smooth muscles from DM rats was lower than that of normal rats. In addition, there were significant differences in percent change of contractility between normal and DM rats following pretreatment with prazosin, udenafil, verapamil, and U73122. In conclusion, we suggest that the decreased bladder muscle contractility in DM rats was a result of perturbations in $PLC/IP_3$-mediated intracellular $Ca^{2+}$ release and PDE5 activity.

• 대한한의학방제학회지
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• 제10권2호
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• pp.143-158
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• 2002

The purpose of the present study is to determine the effect of Jakyakgamchotang on histamine or acetylcholine induced tracheal smooth muscle contraction in rats and guinea pigs. Guinea pig(500g, male) and Sprague Dawley rats(250g, male) were killed by $CO_2$ exposure and a segment (4-5mm) of the thoracic trachea from each rat and guinea pig was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5g loading tension. The dose of histamine(His) which evoked 50% of maximal response($ED_{50}$) was obtained from cumulative dose response curves for histamine($10^{-7}{\sim}10^{-4}M$). Contractions evoked by His($ED_{50}$) were inhibited significantly by Jakyakgamchotang. In guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was 90.8% (p〈0.001) after $100{\mu}l/ml$ Jakyakgamchotang. In rat tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was 22.1% (p〈0.05) after $100{\mu}l/ml$ Jakyakgamchotang. Propranolol indomethacin and methylene blue($10^{-7}M$) slightly but significantly attenuated the inhibitory effects of Jakyakgamchotang. These results indicate that Jakyakgamchotang can relax histamine or acetylcholine induced contraction of guinea pig and rat tracheal smooth muscle.

• Journal of Ginseng Research
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• 제40권4호
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• pp.334-343
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• 2016

Background: Progressed tissue culture techniques have allowed us to easily obtain mass products of tissue-cultured mountain ginseng over 100 yr old (TCMG-100). We investigated the effects of TCMG-100 extract on erectile function using in vitro and in vivo studies. Methods: To examine the relaxation effects and mechanisms of action of TCMG-100 on rabbit cavernosal strips evaluated in an organ bath. To investigate the long-term treatment effect of TCMG-100, 8-wk administration was performed. After administration of TCMG-100, intracavernosal pressure, cyclic guanosine monophosphate and nitric oxide (NO) levels of cavernosal tissue, serum testosterone level, histological observation of collagen fiber, endothelium, smooth muscle cell, and transforming growth factor-${\beta}1$ were investigated. Results: TCMG-100 extract displayed dose-dependent relaxation effects on precontracted rabbit corporal smooth muscle. The TCMG-100-induced relaxation was significantly reduced by removing the endothelium, and treatment with an NO synthase inhibitor or NO scavenger. Eight weeks of TCMG-100 administration increased intracavernosal pressure in a rat model. The levels of cyclic guanosine monophosphate and NO in the corpus callosum and serum testosterone level were also increased by TCMG-100 treatment. Furthermore, histological evaluation of collagen, smooth muscle, and endothelium showed increases in endothelium and smooth muscle, and a decrease in transforming growth factor-${\beta}1$ expression. Conclusion: These relaxation effects on corporal smooth muscle and increased erectile function suggest that TCMG-100 might be used as an alternative herbal medicine to improve erectile function.

• The Korean Journal of Physiology and Pharmacology
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• 제7권1호
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• pp.25-28
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• 2003

Ion channel inhibitors are widely used for pharmacological discrimination between the different channel types as well as for determination of their functional role. In the present study, we tested the hypothesis that 4-aminopyridine (4-AP) could affect the large conductance $Ca^{2+}$-activated $K^+$ channel ($BK_{Ca}$) currents using perforated-patch or cell-attached configuration of patch-clamp technique in the rabbit pulmonary arterial smooth muscle. Application of 4-AP reversibly inhibited the spontaneous transient outward currents (STOCs). The reversal potential and the sensitivity to charybdotoxin indicated that the STOCs were due to the activation of $BK_{Ca}$. The $BK_{Ca}$ currents were recorded in single channel resolution under the cell-attached mode of patch-clamp technique for minimal perturbation of intracellular environment. Application of 4-AP also inhibited the single $BK_{Ca}$ currents reversibly and dose-dependently. The membrane potential of rabbit pulmonary arterial smooth muscle cells showed spontaneous transient hyperpolarizations (STHPs), presumably due to the STOC activities, which was also inhibited by 4-AP. These results suggest that 4-AP can inhibit $BK_{Ca}$ currentsin the intact rabbit vascular smooth muscle. The use of 4-AP as a selective voltage-dependent $K^+$ (KV) channel blocker in vascular smooth muscle, therefore, must be reevaluated.

• Journal of Nutrition and Health
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• 제53권6호
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• pp.563-569
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• 2020

Purpose: The vascular smooth muscle cells (VSMCs) in mature animals have implicated to play a major role in the progression of cardiovascular diseases such as atherosclerosis. This study aimed at optimizing the protocol in culturing primary VSMCs (pVSMCs) from rat thoracic aorta and investigating the effect of cellular zinc (Zn) deficiency on cell proliferation of the isolated pVSMCs. Methods: The thoracic aorta from 7-month-old Sprague Dawley rats was isolated, minced and digested by the enzymatic process of collagenase I and elastase, and then inoculated with the culture Dulbecco Modified Eagle Medium (DMEM) at 37℃ in an incubator. The primary cell culture morphology was observed using phase-contrast microscopy and cellular Zn was depleted using Chelex-100 resin (extracellular zinc depletion only) or 3 µM N,N,N',N'-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine (TPEN) (extracellular and intracellular zinc depletion). Western blot analysis was used for the detection of SM22α and calponin as smooth muscle cell marker proteins and von Willebrand factor as endothelial cell marker protein to detect the culture purity. Cell proliferation by Zn depletion (1 day) was measured by MTT assay. Results: A primary culture protocol for pVSMCs from rat thoracic aorta was developed and optimized. Isolated cultures exhibited hill and valley morphology as the major characteristics of pVSMCs and expressed the smooth muscle cell protein markers, SM22α and calponin, while the endothelial marker von Willebrand factor was hardly detected. Zn deprivation for 1 day culture decreased rat primary vascular smooth muscle cell proliferation and this pattern was more prominent under severe Zn depletion (3 µM TPEN), while less prominent under mild Zn depletion (Chelexing). Conclusion: Our results suggest that cellular Zn deprivation decreased pVSMC proliferation and this may be involved in phenotypic modulation of pVSMC in the aorta.

• Clinical and Experimental Pediatrics
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• 제46권2호
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• pp.167-172
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• 2003

목 적 : 소아 심장병의 주종을 이루고 있는 선천성 심장병 환아들에서 폐동맥 고혈압은 비교적 흔히 발생하지만 매우 치료하기 어려운 합병증이다. 폐동맥 고혈압의 원인과 치료 및 예방에 대해서는 아직 많이 알려지지 않은 실정이므로 이의 원인을 산소결핍이라는 전형을 이용하여 VEGF란 유전인자의 차원에서 규명하고, 나아가서는 폐동맥 고혈압의 치료 및 예방책을 마련하기 위하여 이 연구를 시행하였다. 방 법 : 폐동맥 평활근 세포는 생후 6주 Fischer rat의 주폐동맥을 적출하여 작은 조각으로 잘라 20% fetal bovine serum을 첨가한 DMEM 배지를 사용하여 5% 이산화탄소 배양기에서 배양하였다. 배양된 세포는 평활근 세포에만 선택적으로 염색되는 평활근 myosin과 ${\alpha}$-actin 항체를 이용하여 염색함으로써 순수 평활근 세포임을 확인하였다. 5% 이산화탄소 배양기에서 배양한 대조군 세포와 1 또는 3% $O_2$ tension에서 배양한 실험군 세포에서의 VEGF 발현 차이와 starvation한 군과 하지 않은 군에서의 VEGF 발현 차이를 RT-PCR과 northern blotting을 이용하여 비교하였다. 결 과 : 대조군과 저산소 조건에서 배양한 실험군에서 VEGF 발현 정도는 차이가 없었다. 결 론 : 아직 국내에서는 유전인자 차원에서의 폐동맥고혈압의 원인규명이나 이에 따른 치료에 대한 연구가 전혀 없는 상태이며, 이 연구에 이어 신생쥐와 성숙쥐와의 차이점 및 나아가서 사람과 쥐의 폐동맥 평활근 세포의 차이점 등을 규명할 예정이며, 이번 연구 결과를 바탕으로 폐동맥 고혈압의 원인기전 규명, 치료 및 예방방법 개발에 기여하고자 한다.

• 대한한방내과학회지
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• 제19권1호
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• pp.385-408
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• 1998

Pyeongpaesan (平肺散) has been used in Korea for many centuries as a treatment for respiratory disease. The effect of Pyeongpaesan (平肺散) on tracheal smooth muscle is not known. The purpose of the present study is to determine the effect of Pyeongpaesan (平肺散) on histamine and acetylcholine induced tracheal smooth muscle contraction in rats and guinea pigs. Guinea pig (500 g, male) and Sprague Dawley rats (200 g, male) were killed by $CO_2$ exposure and a segment (8-10 mm) of the thoracic trachea from each rat and guinea pig was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5 g loading tension. The dose of histamine (His) and acetylcholine (Ach) which evoked 50% of maximal response ($ED_{50}$) was obtained from cumulative dose response curves for histamine and acetylcholine $(10^{-7}{\sim}10^{-4}M)$. Contractions evoked by His $(ED_{50})$ and Ach $(ED_{50})$ were inhibited significantly by Pyeongpaesan (平肺散). In guinea pig tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was 13.5% (p<0.05) after $10{\mu}l/ml$ Pyeongpaesan (平肺散), $64.6\(p<0.01)\;after\;30{\mu}l/ml$ Pyeongpaesan (平肺散), and $92.8\(p<0.01)\;after\;100{\mu}l/ml$ Pyeongpaesan (平肺散). In rat tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $60.9\(p<0.01)\;after\;30{\mu}l/ml$ Pyeongpaesan (平肺散), and $91.2\(p<0.01)\;after\;100{\mu}l/ml$ Pyeongpaesan (平肺散). Also, in guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $104.8\(p<0.01)\;after\;30{\mu}l/ml$ Pyeongpaesan (平肺散) and $142.3\(p<0.01)\;after\;100{\mu}l/ml$ Pyeongpaesan (平肺散). In rat tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $63.7\(p<0.01)\;after\;30{\mu}l/ml$ Pyeongpaesan (平肺散), and $107.5\(p<0.01)\;after\;100{\mu}l/ml$ Pyeongpaesan (平肺散). Propranolol $(10^{-7}M)$ slightly but significantly attenuated the inhibitory effects of Pyeongpaesan (平肺散). Following treatment with propranolol, the mean percent inhibition caused by $100{\mu}l/ml$ Pyeongpaesan (平肺散) fell to 15.7% (p<0.05) in guinea pig induced by acetylcholine contraction and the mean percent inhibition caused by $100{\mu}l/ml$ Pyeongpaesan (平肺散) fell to 22.3% (p<0.05) in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Pyeongpaesan (平肺散) fell to 28.7% (p<0.01) in rat induced by histamine contraction. Indomethacin and methylene blue $(10^{-7}\;M)$ did not significantly alter the inhibitory effect of Pyeongpaesan (平肺散). Also, I could find the effects of Pyeongpaesan (平肺散) and Pyeongpaesanga (平肺散加) morphine on the tracheal smooth muscle in guinea pig and rat did not change significantly. These results indicate that Pyeongpaesan. (平肺散) can relax histamine and acetylcholine-induced contraction of guinea pig and rat tracheal smooth muscle, and that this inhibition involves sympathetic effects and the release of cyclooxygenase products.

• Korean Journal of Acupuncture
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• 제18권1호
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• pp.157-164
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• 2001

Radix Asteris has been used in Korea for many centuries as a treatment for respiratory disease. The effect of Radix Asteris on tracheal smooth muscle is not known. The purpose of the present study is to determine the effect of Radix Asteris on histamine induced tracheal smooth muscle contraction in rats and guinea pigs. Guinea pig(500g, male) and Sprague Dawley rats (250g, male) were killed by $CO_2$ exposure and a segment (8-10mm) of the thoracic trachea from each rat and guinea pig was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5g loading tension. The dose of histamine (His) which evoked 50% of maximal response ($ED_{50}$) was obtained from cumulative dose response curves for histamine $(10^{-7}{\sim}10^{-4}M)$. Contractions evoked by His ($ED_{50}$) were inhibited significantly by Radix Asteris. In guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was 120.5% (p<0.01) after $100{\mu}l/ml$ Radix Asteris. In rat tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was 135.4% (p<0.01) after $100{\mu}l/ml$ Radix Asteris. Propranolol $(10^{-7}M)$ slightly but significantly attenuated the inhibitory effects of Radix Asteris. Following treatment with propranolol, the mean percent inhibition caused by $100{\mu}l/ml$ Radix Asteris fell to 44.6% in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Radix Asteris fell to 18.7% (p<0.05) in rat induced by histamine contraction. Indomethacin and methylene blue$(10^{-7}M)$ did not significantly alter the inhibitory effect of Radix Asteris. These results indicate that Radix Asteris can relax histamine induced contraction of guinea pig and rat tracheal smooth muscle, and that this inhibition involves sympathetic effects.

• The Korean Journal of Physiology and Pharmacology
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• 제3권2호
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• pp.119-125
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• 1999

Mammalian gastric smooth muscles generate spontaneous rhythmic contractions which are associated with slow oscillatory potentials (slow waves) and spike potentials. Spike potentials are blocked by organic $Ca^{2+}-antagonists,$ indicating that these result from the activation of L-type $Ca^{2+}-channel.$ However, the cellular mechanisms underlying the generation of slow wave remain unclear. Slow waves are insensitive to $Ca^{2+}-antagonists$ but are blocked by metabolic inhibitors or low temperature. Recently it has been suggested that Interstitial Cells of Cajal (ICC) serve as pacemaker cells and a slow wave reflects the coordinated behavior of both ICC and smooth muscle cells. Small segments of circular smooth muscle isolated from antrum of the guinea-pig stomach generated two types of electrical events; irregular small amplitude (1 to 7 mV) of transient depolarization and larger amplitude (20 to 30 mV) of slow depolarization (regenerative potential). Transient depolarization occurred irregularly and membrane depolarization increased their frequency. Regenerative potentials were generated rhythmically and appeared to result from summed transient depolarizations. Spike potentials, sensitive to nifedipine, were generated on the peaks of regenerative potentials. Depolarization of the membrane evoked regenerative potentials with long latencies (1 to 2 s). These potentials had long partial refractory periods (15 to 20 s). They were inhibited by low concentrations of caffeine, perhaps reflecting either depletion of $Ca^{2+}$ from SR or inhibition of InsP3 receptors, by buffering $Ca^{2+}$ to low levels with BAPTA or by depleting $Ca^{2+}$ from SR with CPA. They persisted in the presence of $Ca^{2+}-sensitive$ $Cl^--channel$ blockers, niflumic acid and DIDS or $Co^{2+},$ a non selective $Ca^{2+}-channel$ blocker. These results suggest that spontaneous activity of gastric smooth muscle results from $Ca^{2+}$ release from SR, followed by activation of $Ca^{2+}-dependent$ ion channels other than $Cl^-$ channels, with the release of $Ca^{2+}$ from SR being triggered by membrane depolarization.

• The Korean Journal of Physiology
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• 제22권1호
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• pp.31-39
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• 1988

This study was carried out to investigate the action of adenosine triphosphate (ATP) on the motility of immature pig uterine smooth muscle. ATP appeared contractile responses in a dose-dependent manner, showing the maximal contraction at the concentration of $10^{-3}M$ in the uterine smooth muscle strip. The contractile responses by $ATP(10^{-4}M)$ were not affected by atropine $(10^{-6}M)$, phentolamine $(10^{-6}M)$, propranolol $(10^{-6}M)$, pyrilamine $(10^{-6}M)$, cimetidine $(10^{-6}M)$, and theophyulline $(5{\times}10^{-5}M)$, but were inhibited uncompetitively by quinidine. The effects of these drugs on the contractile responses by prostaglandin $F_{2{\alpha}}(PGF_{2{\alpha}})$ were also comparable to those observed with ATP. When muscle strips were pretreated with indomethacin $(5{\times}10^{-5}M)$ for 20 min., the contractile responses by $ATP(10^{-4}M)$ were completely inhibited. But the contractile responses by $PGF_{2{\alpha}}$ were not affected by indomethacin. These results suggest that ATP elicited the contraction through noncholinergic- and nonadrenergic-receptor mediated by prostaglandin $F_{2{\alpha}}$ in pig uterine smooth muscle.