• Proceedings of the Korean Biophysical Society Conference
• /
• 2001.06a
• /
• pp.24-24
• /
• 2001

The present study was undertaken to determine whether p38 mitogen-activated protein kinase participates in the regulation of vascular smooth muscle contraction by endothelin-I (ET-1) in rat thoracic aorta. ET-1 induced a sustained contraction. In contrast, both the intracellular Ca$\^$2＋/ and myosin light chain (MLC) phosphorylations were not sustained.(omitted)

• 전기의세계
• /
• v.37 no.7
• /
• pp.81-86
• /
• 1988

임피던스 혈량 측정법(impedance plethysmography)은 인체의 어느 특정부위에서의 혈량의 변화를 환자에게 전혀 고통을 주지않고(noninvasive) 안전하고 간편하게 측정하는 방법으로서, 특히 심장의 빅동량(stroke volume)를 측정하는 분야를 임피던스 카디오그라피(impedance cardiography)라고 한다. 혈량 측정법은 인체의 어느 부위에서 박동하는 혈량은 그 부위로 유입되는 혈량과 유출하는 혈량의 차이 만큼 유발한다는데 근거를 두고 있다. 한편 심전도는 주로 심장의 전기적인 면을 측정하는 반면 임피던스 카디오그라피는 박동량과 심장 근육의 수축능력(contractility)등 심장의 기계적인 면을 측정할 수 있다.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.5 no.2
• /
• pp.92-98
• /
• 2000

Mesangial cell has several key roles in thee control of glomerular function: it partocipates in the regulation of glomerular filtration rate, macromolecular clearance, and as both a source and target of numerous hormones and autocrines. Many of these insights into mesangial cell function have been obtained by studying mesangial cells in culture. However, no suitble cell lines have established yet. We here reported the immortalization of rat kidney glomeruar mesangial cell by transfection of E6 and E7 genes of human papillomavirus type 16 (HPV-16) via electroporation and lipofection. The reslts showed that only electroporation could transfect the genes to mesangial cells and the transfected cells maintained the viability for longer than 6 months. Fluorescence microscopic observation showed that cellular contractility and phagocytosis, which are the two main phenotypes of mesangial cells with rat glomerular epithelial cells showed that the growth of mesangial dells was suppressed by epithelial cell, but the growth of epithelisl cells was enhanced by mesangial cells. Moreover, Such results may imply that the glomerular cell-cell interaction plays an important role in the regulation of cell proliferation and differentiation.

• Biomolecules & Therapeutics
• /
• v.23 no.3
• /
• pp.233-237
• /
• 2015

Shikonin, a natural flavonoid found in the roots of Lithospermum erythrorhizon, has been shown to possess many biological functions. The present study was undertaken to investigate the influence of shikonin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Shikonin significantly relaxed fluoride-, thromboxane $A_2$- or phorbol ester-induced vascular contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, shikonin significantly inhibited fluoride-induced increases in pMYPT1 levels and phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving the inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1 and the inhibition of MEK activity and the subsequent phosphorylation of ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of shikonin on agonist-induced vascular contraction regardless of endothelial function.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.3
• /
• pp.734-739
• /
• 2004

In the present study, the author intended to investigate whether two oriental medical prescriptions named socheongryong-tang(SCRT) and Kamichihyo-san(KCHS) significantly affect mucin release from cultured hamster tracheal surface epithelial(HTSE) cells. Confluent HTSE cells were metabolically radiolabeled with ³H-glucosamine for 24 hrs and chased for 30 min in the presence of SCRT or KCHS to assess the effect of each agent on ³H-mucin release. Possible cytotoxicities of each agent were assessed by measuring lactate dehydrogenase(LDH) release. Also, the effects of SCRT and KCHS on contractility of isolated tracheal smooth muscle were investigated. The results were as follows: (1) SCRT significantly inhibited mucin release from cultured HTSE cells, without cytotoxicity; (2) KCHS significantly increased mucin release without cytotoxicity; (3) SCRT and KCHS did not affect contractility of isolated tracheal smooth muscle. We suggest that the effects of SCRT and its components should be further investigated and it is of great value to find, from oriental medical prescriptions, novel agents which have the possible inhibitory effects on mucin release from the viewpoint of management of hypersecretion of airway mucus.

• BMB Reports
• /
• v.41 no.3
• /
• pp.223-229
• /
• 2008

Reactive oxygen species (ROS) are implicated in vascular homeostasis. This study investigated whether ${O_2}^{\cdot^-}$, the foundation molecule of all ROS, regulates vasomotor function. Hence, vascular reactivity was measured using rat thoracic aortas exposed to an ${O_2}^{\cdot^-}$ generator (pyrogallol) which dose-dependently regulated both $\alpha$-adrenergic agonist-mediated contractility to phenylephrine and endothelium-dependent relaxations to acetylcholine. Pyrogallol improved and attenuated responses to acetylcholine at its lower (10 nM - 1 ${\mu}M$) and higher (10 - 100 ${\mu}M$) concentrations, respectively while producing the inverse effects with phenylephrine. The endothelial inactivation by L-NAME abolished acetylcholine-induced vasodilatations but increased phenylephrine and KCl-induced vasoconstrictions regardless of the pyrogallol dose used. Relaxant responses to sodium nitroprusside, a nitric oxide donor, were not affected by pyrogallol. Other ROS i.e. peroxynitrite and $H_2O_2$ that may be produced during experiments did not alter vascular functions. These findings suggest that the nature of ${O_2}^{\cdot^-}$-evoked vascular function is determined by its local concentration and the presence of a functional endothelium.

• Biomolecules & Therapeutics
• /
• v.22 no.2
• /
• pp.100-105
• /
• 2014

Apigenin, a natural flavonoid found in a variety of vegetables and fruits, has been shown to possess many biological functions. The present study was undertaken to investigate the influence of apigenin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Apigenin significantly relaxed fluoride-, thromboxane $A_2$ mimetic- or phorbol ester-induced vascular contraction, which suggests that apigenin could be an anti-hypertensive that reduces agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, apigenin significantly inhibited fluoride-induced increases in pMYPT1 levels and phorbol ester-induced increases in pERK1/2 levels, which suggests the mechanism involving the inhibition of Rho-kinase and MEK activity and the subsequent phosphorylation of MYPT1 and ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of apigenin on agonist-induced vascular contraction regardless of endothelial function.

• The Journal of Internal Korean Medicine
• /
• v.25 no.2
• /
• pp.238-244
• /
• 2004

Objective : This study is intended to investigate whether the two oriental medical prescriptions, CheongGeumGangHwa-tang(CGGH) and GwaRuJiSil-tang(GRJS), significantly affect mucin release from cultured hamster tracheal surface epithelial(HTSE) cells. Materials and Methods : Confluent HTSE cells were metabolically radio labeled with 3H-glucosamine for 24 hrs and chased for 30 min in the presence of CGGH or GRJS to assess the effect of each agent on 3H-mucin release. Possible cytotoxicities of each agent were assessed by measuring lactate dehydrogenase(LDH) release. Also, the effects of CGGH and GRJS on contractility of isolated tracheal smooth muscle were investigated. Results : (1) CGGH and GRJS significantly increased mucin release from cultured HTSE cells, without cytotoxicity : (2) CGGH and GRJS did not affect contractility of isolated tracheal smooth muscle. Conclusions : These results suggest that the effects of CGGH and GRJS should be further investigated, and that it would be gainful to invesigate, from among oriental medical prescriptions, what novel agents have these mild expectorant effects on mucin secretion from airway goblet cells.

• Annals of Clinical Neurophysiology
• /
• v.19 no.2
• /
• pp.131-135
• /
• 2017

Background: Neuromuscular ultrasound can be used to assess the diaphragm. Before it can be used clinically, the reference ranges of diaphragm thickness and contractility must be determined. Methods: We measured the thickness of the diaphragm and the diaphragmatic thickening fraction (DTF) in 80 healthy volunteers with ultrasound and collected their demographic information to determine if age, sex, and body mass index (BMI) influence these measures. Results: The thickness of the diaphragm at resting end expiration was $0.193{\pm}0.044cm$ on the right side and $0.187{\pm}0.039cm$ on the left. The DTF was $104.8{\pm}50.6%$ on the right side and $114.9{\pm}49.2%$ on the left. Sex, weight, height, and BMI significantly affected the thickness of the diaphragm, but had little effect on the DTF. Conclusions: Normal reference values for the diaphragm should be helpful when evaluating the diaphragm. The DTF appears more useful than resting diaphragm thickness because it is affected less by individual variation.

• The Korean Journal of Pharmacology
• /
• v.8 no.2
• /
• pp.63-69
• /
• 1972

The effects of omission of buffers from Krebs-Ringer medium on contractile activity, membrane potentials and ATP content of electrically stimulated isolated rat atria were investigated. 1) Contractile status: A rapid and marked depression of the contractile activity of atria occurred when buffer-free medium was substituted for the normal Krebs-Ringer medium. 2) Electrical status: The omission of buffers from medium did not alter the resting or action potential magnitudes of atria. However, the action potential duration was on initial increase followed by a decrease in the buffer-free medium. 3) ATP concentration: The omission of buffers from medium resulted in a marked decrease in the ATP levels of atria. It has been also found in the present study that bicarbonate buffer plays an important role for the maintenance of the contractility and ATP levels of the heart. The contractile depression by the omission of buffers was not directly associated with electrical alterations in resting or action potentials of the heart. In the absence of bicarbonate-buffer, glucose no longer plays to maintain the contractile activity and the ATP levels of rat atria.