• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1538-1542
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• 2006

The study was designed to investigate the effects of MokhwyangJoki-san Extract (MJSE) on the change of regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in normal rats, and further to determine the mechanism of MJSE. The results in normal rats were as follows ; MJSE significantly increased rCBF in a dose-dependent manner, and MABP did not change in a dose-dependent manner. This results were suggested that MJSE significantly increased rCBF by dilating pial arterial diameter. The MJSE-induced increase in rCBF was significantly inhibited by pretreatment with methylene blue (10 ${\mu}g/kg$, i.p.), an inhibitor of guanylate cyclase, and was not changed by indomethacin (1 ${\mu}g/kg$, i.p.), an inhibitro of cyclooxygenase. The MJSE-was not changed MABP was decreased by pretreatment with indomethacin but was not changed by methylene blue. This results were suggested that the mechanism of MJSE was mediated by guanylate cyclase.

• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.183-190
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• 2015

Invasive blood pressure (IBP) is measured for the patient's real time arterial pressure (ABP) to monitor the critical abrupt disorders of the cardiovascular system. It can be used for the estimation of cardiac output and the opening and closing time detection of the aortic valve. Although the unexplained inflections on ABP make it difficult to find the mathematical relations with other cardiovascular parameters, the estimations based on ABP for other data have been accepted as useful methods as they had been verified with the statistical results among vast patient data. Previous windkessel models were composed with systemic resistance and vascular compliance and they were successful at explaining the average systolic and diastolic values of ABP simply. Although it is well-known that the blood pressure reflection from peripheral arteries causes complex inflection on ABP, previous models do not contain any elements of the reflections because of the complexity of peripheral arteries' shapes. In this study, to simulate a reflection wave of blood pressure, a new mathematical model was designed with four elements that were the impedance of aorta, the compliance of aortic arch, the peripheral resistance, and the compliance of peripheral arteries. The parameters of the new model were adjusted to have three types of arterial blood pressure waveform that were measured from a patient. It was used to find the relations between the inflections and other cardiovascular parameters such as the opening-closing time of aortic valve and the cardiac output. It showed that the blood pressure reflection can bring wide range errors to the closing time of aortic valve and cardiac output with the conventional estimation based on ABP and that the changes of one-stroke volumes can be easily detected with previous estimation while the changes of heart rate can bring some error caused by unexpected reflections.

• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.199-203
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• 2002

Cardiovascular effects of propofol, were assessed after premedication with xylazine(1.0 mUkg, IM) under oxygen supply(200 ml/kg/min) via a endotracheal tube. Twelve adult mixed-breed dogs were divided into four groups; 0.2(Group 1), 0.4(Group 2), 0.6(Group 3) and 0.8 mg/kg/min(Group 4) of propofol respectively. Arterial blood pressure and electrocardiogram were monitored with a physiograph after an arterial catheter was inserted into the femoral artery. pH, arterial carbon dioxide tension($PaCO_2$and arterial oxygen tension($PaO_2$) were evaluated with arterial blood collected through the inserted catheter. Diastolic arterial pressure, systolic arterial pressure and mean arterial pressure were decreased slightly in Group I IIand III, but decreased significantly in Group IV. They were increased rapidly after stopping propofol infusion in Group IV pH was maintained in normal range in Group I, II and m, but was decreased in proportion to time passing in Group IV. $PaCO_2$ was increased significantly only in Group IV but $PaO_2$ was maintained in normal range in all groups Although heart rate was recorded in normal range for 90 minutes, arythmia was noted after stopping propofol infusion in all groups. It was concluded that propofol depressed the cardiovascular system in proportion to infusion dosage, and 0.8 mg/kg/min of propofol infusion rate was not appropriated in canine anesthesia with xylazine premedication.

• The Korean Journal of Physiology
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• v.11 no.2
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• pp.23-31
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• 1977

It is Proposed in the Present study to investigate the effects of TTX intravenously or intrahypothalamically administered on the arterial blood pressure and respiration and also to explorc effect of intrahypothalamically administered TTX on the pressor responses to electrical stimulation in the hypothalamus. The results obtained are as follows; 1) The pressor responses to electrical stimulation in the hypothalamus were markedly reduced after administration of TTX. In the $0.01\;{\mu}g/kg$ of TTX administered group, the pressor responses were almost abolished in 6 minutes and there was no tendency toward recovery throughout the experiment. 2) In $0.01\;{\mu}g/kg$ of TTX administered group, the mean arterial blood pressure and heart rate-were gradually reduced while there was a transient increase in respiratory rate followed by slow recovery thereafter. On the other hand no changes in arterial blood pressure, heart rate an4 respiration were observed in $0.005\;{\mu}g/kg$ TTX administered group. 3) Following intravenous administration of $1\;{\mu}g/kg$ TTX, the arterial blood pressure and heart rate were slowly reduced by 60 minutes while no marked changes were found in respiration. From the results of present study it is strongly suggested that TTX exerts its depressant effect not only on peripheral nerves but also on central nervous system.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.4
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• pp.143-149
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• 2014

Pulse wave velocity (PWV) is used to non-invasively estimate the severity of arteriosclerosis by measuring the patient's arterial stiffness comparing with each normal reference range according to their ages. Increased arterial stiffness is closely related to both atherosclerosis and arteriosclerosis, which have been known for causes of cardiovascular disease and stroke, also negatively affects the prognosis and the re-occurrence in patients with stroke. The study is focused on how brachial-ankle pulse wave velocity (baPWV) is related to cardiovascular disease risk factors in patients with acute stroke. There were 114 subjects, 69 males and 45 females, all in their 60's and had PWV test for acute stroke. The results are as follows: the group with increased arterial stiffness showed significant increase in HbAlc, total cholesterol, RSBP (resting systolic blood pressure), CSBP (central systolic blood pressure) and CDBP (central diastolic blood pressure). Cross tabulation test showed that there was a significant relationship only between the group with increased arterial stiffness and diabetes mellitus (DM). Therefore, it might be useful for preventing re-occurrence and making a favorable prognosis to promptly adjust DM and hypertension-related risk factors in patients with acute stroke.

• Journal of Sensor Science and Technology
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• v.22 no.1
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• pp.38-43
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• 2013

In this study, the artery's compliance model and the pulsation waveform model was proposed to estimate blood pressure without applying HPF (High Pass Filter) on signal measured by the oscillometric method. The method proposed in the study considered two ways of estimating blood pressure. The first method of estimating blood pressure is by comparing and analyzing changes in pulsation waveform's dicrotic notch region during each cardiac period. The second method is by comparing and analyzing morphological changes in the pulsation waveform during each cardiac period, which occur in response to the change in pressure applied on the cuff. To implement these methods, we proposed the compliance model and the pulsation waveform model of the artery based on hemodynamic theory, and then conducted various simulations. The artery model presented in this study only took artery's compliance into account. Then, a pulsation waveform model was suggested, which uses characteristic changes in the pulsation waveform to estimate blood pressure. In addition, characteristic changes were observed in arterial volume by applying artery's pulsation waveform to the compliance model. The pulsation waveform model was suggested to estimate blood pressure using characteristic changes of the pulsation waveform in the arteries. This model was composed of the sum of sine waves and a Fourier's series in combination form up to 10th harmonics components of the sinusoidal waveform. Then characteristic of arterial volume change was observed by inputting pulsation waveform into the compliance model. The characteristic changes were also observed in the pulsation waveform by mapping the arterial volume change in accordance with applied cuff's pressure change to the pulsation waveform's change according to applied pressure changes by cuff. The systolic and diastolic blood pressures were estimated by applying positional change of pulsation waveform's dicrotic notch region.

• Journal of Veterinary Clinics
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• v.22 no.3
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• pp.220-227
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• 2005

Although ketamine has been used in the field of anesthetic medicine for its safety and favourable respiratory effects, the cardiovascular effects of ketamine is still controversial. To clarify the action and mechanism of ketamine upon cardiovascular system, arterial blood pressure, tension of aortic ring, left ventricular developed pressure and heart rate were measured in rats, Ketamine produced two types of effects on arterial blood pressure in anesthetized rats; monophasic effect (blood pressure lowering) and biphasic effect (initial transient blood pressure increasing following sustained lowering), The ketamine-induced lowering of aterial blood pressure showed a concentration-dependent manner, inhibited by the pretreament of $MgCl_2$ and potentiated by the pretreatment of $CaCl_2$. The ketamine-induced lowering of aterial blood pressure was suppressed by the pretreatment of nifedipine, verapamil or lidocaine. In phenylephrine-precontracted endothelium intact (+E) aortic rings, ketamine sometimes caused a small enhancement of contraction ($112.5{\pm}3.6{\%}$). However, in many experiments, ketamine produced a concentration-dependent relaxation in +E aortic rings precontracted with either phenylephrine or KCl. Ketamine-induced relaxation was significantly greater in KCl-precontracted strips than phenylephrine-precontracted strips. In phenylephrine-precontracted +E aortic rings, the ketamine-induced vasorelaxation was not suppressed by endothelium removal or by the pretreatment of a nitric oxide synthase inhibitors, L-$N^G$-nitro-arginine and a guanylate cyclase inhibitors, methylene blue, suggesting that the ketamine-induced vasorelaxation is not dependent on the endothelial function. In addition, ketamine elicited an increase in left ventricular developed pressure in perfused hearts accompanied by decrease in heart rate. These results suggest that ketamine could evoke a hypotension due to vasorelaxation and decrease in heart rate in rats. The inhibitory effect of cardiovascular system might be associated with modulation of $Ca^{2+}$ homeostasis.

• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.411-417
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• 2000

This paper describes the analysis of the oscillometric method based on the shape of arterial pressure and proposal of a new algorithm for estimating the blood pressure by computer simulation. In the first step, the arterial pressure model which is able to control the shape of arterial pressure was designed and then we simulated the oscillometric model using both the existing exponential model showing the static arterial pressure-volume relation and the designed arterial pressure model. By analyzing the correlation of characteristic ratio based on the shape of arterial pressure, we could find that the characteristic ratio was not the only standard parameter for estimating systolic and diastolic pressure. We were able to estimate the shape of arterial pressure by computing the correlation of arterial pressure shape with oscillation shape. Finally, we proposed an algorithm which is able to estimate systolic and diastolic pressure according to pressure(Pp) table constructed from the relation of maximum amplitude of oscillation and arterial pressure shape. We tested 60 arterial pressure waveforms having various arterial pressure shape and pulse. As a results, the absolute deviation average values of the estimation of systolic, diastolic and mean pressure were 1.62%, 2.40% and 2.20%, respectively. In conclusions, the proposed algorithm showed the possibility of usefullness in estimating the blood pressure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1926-1938
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• 2009

In this study, detection system of the blood flow variation rate was implemented using the variation effect of bio electric impedance at time of the blood pressure measurement by means of impedance method. The blood pressure measurement was performed by the oscillometric method. The mean arterial pressure was calculated using maximum amplitude algorithm. The systolic and diastolic pressure were estimated by establishment of the various characteristic ratio according to mean arterial pressure range. Alternative static current source and lock_in amplifier were introduced to impedance measurement. The variation of blood volume was measured using variation bio impedance according to induced cuff pressure at measuring area.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.370-373
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• 1998

Ten substituted phenacyl derivatives of 4-hydroxypiperidine were synthesized and studied for their effects on the mean arterial blood pressure (MABP) in normotensive anaesthetized rats and smooth muscles contractions of isolated rabbit jejunum. Two derivatives caused fall in blood pressure at the dose of 10-20 mg/kg and one rise in blood pressure at the dose of 20 mg/kg. Two compounds exhibited biphasic response (hypotensive followed by hypertensive) and one gave triphasic response at 10 mg/kg dose. Rest of four derivatives were found devoid of any effect on mean arterial blood pressure up to the dose of 30 mg/kg. All the derivatives except two caused relaxant effect on the spontaneous contraction of rabbit jejunum at the dose range of 0.1 -2 mg/kg.