• 동의생리병리학회지
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• 제22권2호
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• pp.315-320
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• 2008

This study investigated the signaling mechanisms contributed to the vasodilatory effects of HMC05, a herbal prescription. HMC05 acted in an endothelium-independent manner. To elucidate the fundamental mechanisms of its vascular actions, we focused on the signaling molecules involved in actin-myosin filament regulation including 20 kDa myosin light chains (LC20), Rho-associated kinase (ROCK), PKC, JNK and extracellular signal-regulated protein kinase (ERK) in the endothelium-denuded thoracic aorta or isolated smooth muscle cells (SMCs). It lowered the phosphorylation level of LC20 and showed that ROCK, ERK, JNK and $PKC{\alpha}$ pathways played important roles in the effects, as confirmed by the observations with a specific inhibition or activation, and with the activity and the subcellular localization of these molecules. In particular, HMC05 dramatically inhibited the activity of ERK and the downstream signaling of ROCK. It also changed the subcellular localization of the phophorylated $PKC{\alpha}$ as well as the amount of phosphorylation. Taken together, these data indicate that the vascular relaxation effects of HMC05 are attributed to the regulation of these signaling mechanisms.

• 한국축산식품학회지
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• 제44권1호
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• pp.216-224
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• 2024

The reduction of nitric oxide (NO) bioavailability in the endothelium induces endothelial dysfunction, contributing to the development of hypertension. Although Lactobacillus consumption decreases blood pressure, intracellular signaling pathways related to hypertension have not been well elucidated. Thus, this study examined the effect of spray-dried Lactiplantibacillus plantarum K79 (LpK79) on NO production, intracellular signaling pathways, and inflammatory responses related to vascular function and hypertension. NO production was assessed in human umbilical vein endothelial cells (HUVECs) treated with LpK79. Endothelial NO synthase (eNOS) and intracellular signaling molecules were determined using Western blot analysis. LpK79 dose-dependently increased NO production and activated eNOS via the phosphoinositide 3-kinase/Akt signaling pathway HUVECs. Moreover, LpK79 mitigated the activation of crucial factors pivotal for vascular contraction in smooth muscle cells, such as phospholipase Cγ, myosin phosphatase target subunit 1, and Rho-associated kinase 2. When HUVECs were treated with LpL79 in the presence of Escherichia coli lipopolysaccharide (LPS), LpK79 effectively suppressed mRNA and protein expression of pro-inflammatory mediators induced by E. coli LPS. These results suggest that LpK79 provided a beneficial effect on the regulation of vascular endothelial function.

• The Korean Journal of Physiology and Pharmacology
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• 제1권5호
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• pp.555-563
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• 1997

The effects of pH on $K^+$ currents were investigated in single smooth muscle cells isolated from the thoracic aorta of Wistar-Kyoto rats. Whole-cell $K^+$ currents were recorded in the conventional configuration of the voltage-clamp technique. Pinacidil (10uM) activated the whole-cell current and the pinacidil-activated current was completely inhibited by glibenclamide (10uM) , an inhibitor of ATP-sensitive $K^+$ channel ($K_{ATP}$ channel). Pinacidil-activated current was reversed at near the $K^+$ equilibrium potential. This current was time- and voltage-independent and reduced by elevating intracellular ATP. Pinacidil-activated current was reduced by lowering the external pH. However, alteration of internal pH has controversial effects on pinacidil-activated current. When the single cell was dialyzed with 0.1 mM ATP, alteration of internal pH had no effect on pinacidil-activated $K^+$ current. In the contrast, when the single cell was dialyzed with 3 mM ATP, pinacidil-activated current was increased by lowering internal pH. Our results suggest that $K^+$ channel activated by pinacidil may be $K_{ATP}$ channel and internal $H^+$ may reduce the inhibitory effect of ATP on $K_{ATP}$ channel.

• Archives of Pharmacal Research
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• 제29권1호
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• pp.34-39
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• 2006

The antispasmodic and vasodilator activities of a newly synthesized piperidine derivative (1-(4'fluorophenacyl)-4-hydroxy-4-phenyl-piperidinium chloride) were studied in vitro. The test compound exhibited a dose-dependent relaxant effect on the spontaneous and $K^+$ (75 mM)-induced contractions of isolated rabbit jejunum with respective $EC_{50}$ values of 0.01 mM(0.01-0.02, 95% CI) and 0.30 mM (0.17-0.56). The $Ca^{++}$ channel blocking (CCB) activity was confirmed when the test compound (0.1-0.2 mM) shifted the $Ca^{++}$ dose-response curves to the right, similar to that produced by verapamil ($0.1-1.0{\mu}M$), a standard CCB. In the isolated rabbit aorta, the test compound showed a dose-dependent vasodilator effect on $K^+$ (75 mM)-induced contractions with an $EC_{50}$ value of 0.08 mM (0.02-0.26) while also suppressed the norepinephrine ($1{\mu}M$) control peak responses with $EC_{50}$ value of 0.08 mM (0.05-0.13, n=5). When tested in Langendorff perfused rabbit heart preparation, the test compound exhibited a negligible inhibitory effect on the rate or force of atrial and ventricular contractions when tested up to 5 mM. The results show smooth muscle-selective relaxant effect of the test compound on intestinal and vascular preparations mediated possibly via blockade of voltage and receptor-operated $Ca^{++}$ channels.

• 약학회지
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• 제41권6호
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• pp.797-801
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• 1997

Recently we reported that water extracts of Coptidis Rhizomas showed calcium antagonistic action and alpha-adrenoceptor inhibitory action in the vascular smooth muscle. Since ca lcium antagonistic properties are important in the treatment of various diseases including asthma. In the present study, the bronchodilatory effects of crude extract of three kinds of Coptidis Rhizoma (Coptidis chinensis, Coptis japonica and root hair of Coptis japonica) was investigated using rat isolated trachea. The result showed that all extracts relaxed carbachol-contracted tracheal smooth muscle. Concentration-dependently, in which the root hair of Coptis japonica was the least potent. The inhibitory potency expressed in terms of $IC_{50}$ against carbachol contraction was 1.8${\mu}$g/ml and 2.7${\mu}$g/ml for Coptidis chinensis and Coptis japonica, respectively. These extracts also inhibited KCI-contracted tracheal smooth muscle. But the relative potency ($IC_{50}$) was 3.5 and 4.1 folds weaker than carbachol-induced contraction for Coptidics chinenesis and Coptis japonica, respectively. Pretreatment of crude extracts also inhibited carbachol- or KCI-induced contraction, non-competitively. These findings indicate that the extracts have muscarinic blocking as well as $Ca^{2+}$ channel blocking action. When provoked intracellular stored $Ca^{2+}$ release by carbachol in $Ca^{2+}$-free conditions, initial phasic contraction due to $Ca^{2+}$ release was significantly inhibited by the extracts. As taken together, we conclude that water extracts of Coptidis Rhizoma may be beneficial in bronchospasm or other broncheal tube narrowing conditions such as asthma.

• 대한의용생체공학회:의공학회지
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• 제29권1호
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• pp.52-58
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• 2008

The object of this study is to investigate the effects of intermittent cyclic stretching on the smooth muscle cells (SMCs) seeded onto aligned multi-layered fibrous scaffold. To make multi-layered fibrous scaffold, polyurethane (PU) and poly(ethylene oxide) (PEO) were electrospun alternatively, then were immersed into distilled water to extract PEO. Various types of scaffolds were fabricated depending on fiber directions, i.e., aligned or randomly oriented. The direction of stretching was either parallel or vertical to the fiber direction for the aligned scaffolds. The stretching was also applied to the randomly aligned scaffolds. The duration of stretching was 2 min with 15 min resting period. During the stretching, the maximum and minimum strain was adjusted to be 10 and 7%, respectively with the frequency of 1 Hz. The bioactivities of cells on the scaffolds were assessed by quantifying DNA, collagen, and glycosaminoglycan (GAG) levels. And the cell morphology was observed by staining F-actin. SMCs under parallel stretching to the fiber direction responded more positively than those in other conditions. From the results, we could explain the morphological effect of a substrate on cellular activities. In addition the synergistic effects of substrate and mechanical stimuli effects were confirmed.

• The Korean Journal of Physiology and Pharmacology
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• 제13권2호
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• pp.107-113
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• 2009

Olibanum (Boswellia serrata) has been shown to have anti-inflammatory, anti-arthritic and anticancer effects. This study determined the role of a water extract of olibanum in platelet-derived growth factor (PDGF)-stimulated proliferation and migration of rat aortic smooth muscle cells (RASMCs). PDGF-BB induced the migration and proliferation of RASMCs that were inhibited by olibanum extract in a dose-dependent manner. The PDGF-BB-increased phosphorylation of p38 mitogen-activated protein kinase (MAPK); the heat shock protein (Hsp) 27 was significantly inhibited by the olibanum extract. The effects of PDGF-BB-induced extracellular signal-regulated kinase1/2 was not altered by the olibanum extract. Treatment with olibanum extract inhibited PDGF-BB-stimulated sprout out growth of aortic rings. These results suggest that the water extract of olibanum inhibits PDGF-BB-stimulated migration and proliferation in RASMCs as well as sprout out growth, which may be mediated by the inhibition of the p38 MAPK and Hsp27 pathways.

• Molecules and Cells
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• 제27권2호
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• pp.191-198
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• 2009

The present study was undertaken to determine whether treatment with genistein, the plant-derived estrogen-like compound influences agonist-induced vascular smooth muscle contraction and, if so, to investigate related mechanisms. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Genistein completely inhibited KCl-, phorbol ester-, phenylephrine-, fluoride- and thromboxane $A_2$-induced contractions. An inactive analogue, daidzein, completely inhibited only fluoride-induced contraction regardless of endothelial function, suggesting some difference between the mechanisms of RhoA/Rho-kinase activators such as fluoride and thromboxane $A_2$. Furthermore, genistein and daidzein each significantly decreased phosphorylation of MYPT1 at Thr855 had been induced by a thromboxane $A_2$ mimetic. Interestingly, iberiotoxin, a blocker of large-conductance calcium-activated potassium channels, did not inhibit the relaxation response to genistein or daidzein in denuded aortic rings precontracted with fluoride. In conclusion, genistein or daidzein elicit similar relaxing responses in fluoride-induced contractions, regardless of tyrosine kinase inhibition or endothelial function, and the relaxation caused by genistein or daidzein was not antagonized by large conductance $K_{Ca}$-channel inhibitors in the denuded muscle. This suggests that the RhoA/Rho-kinase pathway rather than $K^+$- channels are involved in the genistein-induced vasodilation. In addition, based on molecular and physiological results, only one vasoconstrictor fluoride seems to be a full RhoA/Rho-kinase activator; the others are partial activators.

• The Korean Journal of Physiology
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• 제28권2호
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• pp.169-179
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• 1994

The effect of extracellular and intracellular pH on vascular tone and $^{45}Ca$ uptake were investigated in aortic strips and dispersed single aortic smooth muscle cells of spontaneously hypertensive rats (SHR) and aged-matched Wistar-Kyoto rats (WKY). The contraction produced by a change of extracellular pH (pHo) in the range of $6.5{\sim}8.3$ was estimated by comparison with the level of vascular tone at pH 7.4. Contraction was induced below pHo 6.5 in WKY, pHo 7.1 in SHR, and over pHo 8.0 on both strains. The amplitude of contraction induced by high pHo (over pHo 7.7) was similar in SHR and WKY, but that induced by low pHo (below pHo 7.1) in SHR was greater than that in WKY. Either high pHo- or low pHo-induced contractions in WKY and SHR were not induced in the Ca-free Tyrode's solution and were induced by the addition of Ca. $^{45}Ca$ uptake increased progressively as pHo was increased from 6.8 to 8.1 in the single aortic smooth muscle cells of WKY and SHR. $NH_4Cl$ induced a gradually developing contraction in a dose-dependent manner $(5\;mM{\sim}30\;mM)$ and the removal of $NH_4Cl$ induced transient contraction was followed by profound relaxation in the aortic rings of both strains. The contractions induced by $NH_4Cl$ or by the removal of $NH_4Cl$ in SHR were significantly greater than that in WKY. These contractions were not induced in Ca-free Tyrode's solution. $^{45}Ca$ uptake was increased by $NH_4Cl$ (20 mM) and was not changed by the removal of $NH_4Cl$ (20 mM) in the aortic strips of WKY and SHR. As a summary of above results, the vascular tone of SHR was more sensitive to the change pHi and pHo than that of WKY. The contractions induced by change of extracellular or intracellular pH depended on extracellular Ca in the aorta of SHR nnd WKY. However, the Ca uptake was in accord with the changes of contraction but increase in contraction by low pH was not accompanied by an increase in Ca uptake in both strains.

• Journal of Chest Surgery
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• 제28권8호
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• pp.742-746
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• 1995

The present study was aimed at investigating possible transmitter mechanisms in the endothelial cell layer in regulating the tone of the vascular smooth muscle. The thoracic aorta was isolated from the anesthetized male white rabbits and its helical strips were prepared. Electrical field stimulation was delivered to platinum wire electrodes positioned parallel to the vessel segment preconstricted with phenylephrine [3.5x10-6 mol/L at a distance of 1.5-2.0 mm. The electrical stimulation [70 V, 5 msec, 0.5-200 Hz caused either relaxation only [34% or a biphasic response [prolonged relaxation following a weak and transient contraction, 66% . The relaxation response was frequency- dependent, and at 200 Hz a complete relaxation was noted. Mechanical rubbing of the endothelial layer abolished or greatly attenuated the relaxation. The relaxation was also markedly attenuated in the presence of NG-nitro- L-arginine methyl ester [10-3mol/L or procaine hydrochloride [3.5x10-4mol/L . Tetrodotoxin,guanethidine, atropine or indomethacin failed to block or enhance the relaxation response to electrical field stimulation. It is concluded that the vascular endothelium in the aorta contains diffusible substances that regulates the function of the smooth muscle layer, in which relaxation is more prominent than contraction. Their release by the electrical stimualtion in vitro may not involve classic neuronal transmitter release mechanisms or metabolism of arachidonic acids by cyclooxygenase. The release of the relaxing agents may require an increase in cytosolic calcium level. The chemical nature of the relaxant may be, to a large extent, nitric oxide.