• 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.

• Annals of Clinical Neurophysiology
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• 제25권2호
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• pp.66-77
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• 2023

Orthostatic hypotension is a sustained and pathological drop in blood pressure upon standing. Orthostatic hypotension can be due to non-neurogenic conditions or autonomic disorders. Impaired baroreflex-mediated vasoconstriction and insufficient release of norepinephrine play key roles in the pathophysiology of neurogenic orthostatic hypotension. Its common symptoms mainly related to inadequate cerebral blood flow include dizziness, lightheadedness, and syncope. It is crucial to differentiate neurogenic orthostatic hypotension from non-neurogenic orthostatic hypotension. For the management of neurogenic orthostatic hypotension, physicians should implement non-pharmacological methods and, if possible, reverse combined non-neurological conditions. Depending on severity of symptoms, pharmacological intervention may be tried after or with non-pharmacological methods. Its management should be individualized based on intensity of symptoms, comorbid conditions, drug side effects, and etiology. In this review, we discuss the definition, pathophysiology, clinical approach, and management of neurogenic orthostatic hypotension.

• 대한물리치료과학회지
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• 제13권2호
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• pp.137-145
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• 2006

We investigated whether increased contractile responsiveness to epidermal growth factor (EGF) is associated with altered activation of mitogen-activated protein kinase (MAPK) in the aortic smooth muscle of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. EGF induced contraction and MAPK activity in aortic smooth muscle strips, which were significantly increased in tissues from the DOCA-salt hypertensive rats compared with those from sham-operated rats. AG1478, PD98059, and LY294002, inhibitors of EGF receptor (EGFR) tyrosine kinase, MAPK/extracellular signal-regulated kinase (ERK) kinase, and phosphatidylinositol 3-kinase (PI3K), respectively, inhibited the contraction and the activity of ERK1/2 that were elevated by EGF. Y27632 and GF109203X, inhibitors of Rho kinase and protein kinase C, respectively, attenuated EGF-induced contraction, with no diminution of ERK1/2 activity. Although EGF also elevated the activity of EGFR tyrosine kinase in both sham-operated and DOCA-salt hypertensive rats, the expression and the magnitude of activation did not differ between strips. These results strongly suggest that EGF induces contraction by the activation of ERK1/2, which is regulated by the PI3K pathway in the aortic smooth muscle of DOCA-salt hypertensive rats.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 1999년도 제3회 전자장의 생체영향에 관한 워크숍
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• pp.117-129
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• 1999

Acute effects of locally applied of static magnetic field (SMF) and extremely low frequency electromagnetic field(ELF-EMF) to the cutaneous tissue within a rabbit ear chamber (REC)were evaluated under conscious conditions. Rabbits with the REC were subjected to intravital microscopical investigation by use of microphotoelectric plethysmography(MPPG). There was no dose-response relationship between the extent of vasomotion changes and frequencies(0,20,50, 100Hz)or power levels (1, 5, 10, 25, 50, 100, 200 mT). Under low vascular tone the both fields induce vasodilatation. The effects of SMF (1 mT) on the cutaneous microcirculatory system induced the vasodilatation with enhanced vasomotion under nor-adrenaline-induced high vascular tone as well as the vasoconstriction with reduced vasomotion under acetylcholine-induced low vascular tone. This suggests that the SMF can modulate vascular tone due to the modification of vasomotion biphasically in the cutaneous tissue.

• Biomolecules & Therapeutics
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• 제16권3호
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• pp.249-254
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• 2008

The present study was undertaken to determine whether hypoxia influences on the agonist-induced vascular smooth muscle contraction and, if so, to investigate the related mechanism. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Hypoxia significantly inhibited fluoride-induced contraction regardless of endothelial function, but there was no relaxation on thromboxane $A_2$ mimetic U-46619-induced contraction suggesting that other pathway such as $Ca^{2+}$ entry or thin filament regulation was not affected. In addition, hypoxia significantly decreased fluoride-induced increase of phospho-myosin-targeting subunit of myosin light chain phosphatase (pMYPT1). Interestingly, hypoxia didn't inhibit significantly phenylephrine-induced contraction suggesting that myosin light chain kinase (MLCK) activity or thin filament regulation is less important on the hypoxia-induced vasorelaxation in the denuded muscle than Rho-kinase activity. In conclusion, this study provides the evidence and possible related mechanism concerning the vasodilation effect of hypoxia on the agonist-specific contraction in rat aortic rings regardless of endothelial function.

• Journal of Chest Surgery
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• 제38권3호
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• pp.245-248
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• 2005

에르고타민이 포함된 약물은 편두통의 치료에 널리 사용되고 있다. 경련성의 혈관수축은 가장 심각한 약물 부작용 중의 하나로 이는 허용된 약물 투여량의 복용에서도 일어날 수 있다. 저자는 15년간 편두통으로 인해 꾸준히 에르고타민이 포함된 약물을 복용한 과거력이 있는 63세 남자환자에 나타난 혈관경축에 의한 상지의 심한 허혈상태를 인조혈관 우회로 이식술, 교감신경 차단술, 그리고 헤파린과 프로스타글란딘 El으로 치료하였으나 결국 에르고타민이 포함된 약물을 중단하고서야 극적인 임상 호전을 경험하였기에 보고하는 바이다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.192-192
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• 1996

Endothelin has $ET_{A}$ type and $ET_{B}$ type receptors, and it has been thought that ET-1 proves vasoconstriction effect via $ET_{A}$ receptor and vasodilation via $ET_{B}$ receptor. Recently, it has been reported that $ET_{B}$ receptor is also related to the vaso-constriction. Bosentan is a $ET_{A+B}$ receptor antagonist, and proves it's effect on trauma and ischemia. We already announced that the level of Endothelin-1 increase in the brain and spinal cord of EAE-induced lewis rat and showed the origin of ET-1 is activated macrophages. Intracisternal injection of Bosentan, $ET_{A+B}$ receptor antagonist, (300nmol/body) was done for observing the role of endothelin-1 on the pathogenesis of EAE. Bosentan ameliorated the severity of clinical score of EAE and decreased the histologically observed inflammatory region. The blocking effect on the progression of EAE model suggests that Bosentan is a physiological antagonist in terms of development of the sign of multiple sclerosis.

• Toxicological Research
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• 제17권
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• pp.117-125
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• 2001

Envenoming by Russells viper causes a broad spectrum of renal impairment. Renal failure is an important complication in patients bitten by Russells viper. Experimental work in animals and in vitro has elucidated pathophysiological mechanisms that contribute to life threatening complications and have suggested possibilities for therapeutic intervention. The evidence in experimental animals regarding mechanisms of venom action in relation to changes in either extrarenal or intrarenal factors is presented. The cardiovascular system and renal hemodynamics are affected by venom. Reductions of renal function including renal hemodynamics are associated directly with changes in general circulation during envenomation. Possible endogenous mechanisms for releasing the hormone inducing renal vasoconstriction after envenomation are evident. Hormonal factor such as the catecholamine, prostaglandin and renin angiotensin systems induce these changes. Direct nephrotoxicity of venom action is studied in the isolated per-fused kidney. Characteristic polarization of the cell membrane, changes of mitochondrial activity and Na-K ATPase in renal tubular cells are observed. Changes in renal function and the cardiovascular system are observed of ter envenomation and are reversed by the administration of Russells viper antivenom (purified equine immunoglobulin, $Fab_2$ fragment). The neutralizing effects are more efficient when the intravenous injection of antivenom is given within 30 min after the envenomation.

• 한국의류학회지
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• 제23권7호
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• pp.965-970
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• 1999

This study was conducted to investigate the thermoregulatory characteristics of feet and legs by comparing with the physiological responses according to the covering parts of lower limbs. Five healthy female subjects wore three types of clothing-covered legs and feet(LF-C) with long trousers and socks exposed the legs(L-E) with half trousers and socks and exposed the legs and feet(LF-E) with only half trousers-when the subjects rested at $25^{\circ}C$ and were exposed to 18$^{\circ}C$ for 90 min. Rectal temperatures (Tre) were maintained higher in LF-E than L-E and LF-C at both environments. Decreases of The after exposure to 18$^{\circ}C$ were significantly smaller in LF-E than L-E and LF-C and almost same in L-E and LF-C Heat production in both environments increases of heat production and weight loss after exposure to 18$^{\circ}C$ were not significant among three types of clothing. From these findings it would be suggested that the legs would play the little role of voluntary thermoregulation as vasoconstriction and the role of the legs depend on thermal conditions of feet while the feet play the positive role of voluntary thermoregulation in terms of heat conservation in cool environment.

• 셀메드
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• 제5권4호
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• pp.27.1-27.6
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• 2015

Literatures and experimental studies have shown that Prunella has an effect on anti-hypertension, however, its components are complicated, so that it is still difficult to clear the specific roles of its various components in blood pressure regulation in. So we decide to systematically study the anti-hypertension mechanism of Prunella. We integrated multiple databases and constructed molecular interaction network between the chemical constituents of Prunella Vulgaris and hypertension based on entity grammar systems model. The network has 262 nodes and 802 edges. Then we infer the interactions between chemical compositions and disease targets to clarify the anti-hypertension mechanism. Finally, we found Prunella could influence hypertension by regulating apoptosis, cell proliferation, blood vessel development and vasoconstriction, etc. Thus this study provides reference for drug development and compatibility, and also gives guidance for health care at a certain extent.