• YAKHAK HOEJI
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• v.55 no.3
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• pp.247-250
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• 2011

An increase in ventricular pressure can alter cardiac excitation and contraction. Recent report has demonstrated that fluid pressure (FP) suppresses L-type $Ca^{2+}$ current with acceleration of the current inactivation in ventricular myocytes. Since the L-type $Ca^{2+}$ channels known to be regulated by intracellular pH ($pH_i$), this study was designed to explore whether pressurized fluid flow affects pHi in isolated rat ventricular myocytes. A flow of pressurized (~16 dyne/$cm^2$) fluid, identical to that bathing the myocytes, was applied onto single myocytes, and intracellular $H^+$ concentration was monitored using confocal $H^+$ imaging. FP significantly decreased $pH_i$ by $0.07{\pm}0.01$ pH units (n=16, P<0.01). Intracellular acidosis enhances the activity of $Na^+-H^+$ exchanger (NHE). Therefore, we examined if the NHE activity is increased by FP using the NHE inhibitor, HOE642. Although HOE642 did not alter $pH_i$ in control conditions, it decreased $pH_i$ in cells pre-exposed to FP, suggesting enhancement of NHE activity by FP. In addition, FP-induced intracellular acidosis was larger in cells pre-treated with HOE642 than in cells under the control conditions. These results suggest that FP induces intracellular acidosis and that NHE may contribute to extrude $H^+$ during the FP-induced acidosis in rat ventricular myocytes.

• Journal of Chest Surgery
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• v.12 no.4
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• pp.395-402
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• 1979

Intracellular pH was determined by distribution of 5.5-dimethyl-2,4-oxazolidlnedione [DMO]in the skeletal muscle of dogs before and after lactic acidosis induced by intravenous infusion of lactic acid solution. After infusion of lactic acid solution arterial pH decreased from 7.40 to around 7.12 [P<0.001]and metabolic acidosis was induced. However, dose-pH change response was not proportional as in the case of hydrochloric acid infusion. During lactic acidosis, intracellular pH changed very little except when venous blood $pCO_2$ increased significantly. The decrease of intracellular pH in lactic acidosis might be due primarily to the increase of intracellular $pCO_2$. And during lactic acidosis, change of extracellular pH was larger than that of intracellular pH, and this was also the case of change In hydrogen Ion concentration in extracellular and intracellular fluid. The fact was estimated that exogenous lactic acid transported into the cell does not contribute to pH change by the participation in the metabolism. Change in plasma potassium Ion concentration was not eminent as metabolic acid-base disturbances by other origin, and changing pattern of Hi/He ratio was not same as Ki/Ke ratio. In spite of no changes in extracellular potassium ion concentration after exogenous lactic acidosis total amount of potassium ion in extracellular fluid increased from 12.62mEg to 18.26mEg [P< 0.05].

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.5
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• pp.563-569
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• 2013

This study was undertaken to apply the yin-yang theory in action potential. In order to apply the yin-yang theory in action potential, nature of yin and yang, interrelation of yin and yang and action potential in cell were reviewed. According to the yin-yang theory, inner cellular space corresponds to yin, but outer cellular space corresponds to yang. If we classify ions in intracellular fluid or extracellular fluid by nature of yin and yang, potassium(K+) corresponds to yang within yin(陰中之陽), protein(Pr-) corresponds to yin within yin(陰中之陰) in intracellular fluid, and sodium(Na+) corresponds to yang within yang(陽中之陽), chloride(Cl-) corresponds to yin within yang(陽中之陰) in extracellular fluid. Double donnan equilibrium and equilibrium potential were caused by intracellular anion(Pr-) and extracellular cation(Na+) are related with mutual rooting of yin and yang(陰陽互根) and opposition of yin and yang(陰陽對立). The influx and efflux of ion through cell membrane means waxing and waning of yin and yang(陰陽消長), the change of membrane potential means yin-yang conversion(陰陽轉化) during action potential.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1236-1239
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• 2004

The object of this study is to develop a model of the cardiovascular system capable of simulating the short-term transient and steady-state hemodynamic responses such as hypotention and disequilibrium syndrome during hemodialysis or hemofiltration. The model consists of a closed loop 12 lumped-parameter representation of the cardiovascular circulation connected to set-point models of the arterial and cardiopulmonary baroreflexes and 3 compartmental body fluid and solute kinetic model. The hemodialysis model includes the dynamics of sodium, urea, and potassium in the intracellular and extracellular pools, fluid balance equations for the intracellular, interstitial, and plasma volumes. We have presented the results of many different simulations performed by changing a few model parameters with respect to their basal values.

• Journal of Korean Physical Therapy Science
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• v.10 no.1
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• pp.140-148
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• 2003

This study examined the relationship between body fitness and body composition as well as the body fluid and intracellular fluid (ICF) of extremities to determine body composition's quantitative criteria for body fitness. Multiple-frequency segmental bioelectrical impedance analysis and the physical fitness test provided by the Ministry of Education, Culture, Sports, Science and Technology were used to measure body composition and physical fitness, respectively. The test results showed that in women in their fifties, the correlation between the amount of body fluid in the upper limbs and grip strength was r=.654 (p<0.01) for the right arm and r=.445 for the left while that between the amount of ICF in the upper limbs and grip strength was r=.708 (p<0.01) for the right and r=.323 for the left. Also, in women in their fifties, the correlation between the amount of body fluid in the lower limbs and the result of a repetitive side jump test was r=.730 for the right leg and r=.753 for the left (p<0.01 for both), and that between the amount of ICF and the counts for the right and left legs was even higher with r=.742 and r=.763, respectively (p<0.01 for both). The body fluid and ICF volumes in the right extremities exceeded those in the left, and physical fitness was correlated with both body fluid and ICF. These findings indicate a connection between physical fitness and body fluid and ICF, suggesting that body composition may help predict physical fitness.

• International Journal of Oral Biology
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• v.35 no.3
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• pp.129-135
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• 2010

Recent studies have implicated reactive oxygen species (ROS) as determinants of the pathological pain caused by the activation of peripheral neurons. It has not been elucidated, however, how ROS activate the primary sensory neurons in the pain pathway. In this study, calcium imaging was performed to investigate the effects of NaOCl, a ROS donor, on the intracellular calcium concentration ($[Ca^{2+}]i$) in acutely dissociated dorsal root ganglion (DRG) neurons. DRG was sequentially treated with 0.2 mg/ml of both protease and thermolysin, and single neurons were then obtained by mechanical dissociation. The administration of NaOCl then caused a reversible increase in the $[Ca^{2+}]i$, which was inhibited by pretreatment with phenyl-N-tertbuthylnitrone (PBN) and isoascorbate, both ROS scavengers. The NaOCl-induced $[Ca^{2+}]i$ increase was suppressed both in a calcium free solution and after depletion of the intracellular $Ca^{2+}$ pool by thapsigargin. Additionally, this increase was predominantly blocked by pretreatment with the transient receptor potential (TRP) antagonists, ruthenium red ($50\;{\mu}M$) and capsazepine ($10\;{\mu}M$). Collectively, these results suggest that an increase in the intracellular calcium concentration is produced from both extracellular fluid and the intracellular calcium store, and that TRP might be involved in the sensation of pain induced by ROS.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.1
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• pp.36-41
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• 2006

Objective. The objective of this study was to examine the hypothesis that inflammatory synovial fluid from TMJ internal derangement initiates a transient increase in intracellular calcium concentration ([$Ca^{2+}$]i) in chondrocytes and the induced Ca2+ signaling affects iNOS/COX-2 gene expression patterns following exposure to inflamed synovial fluid. Materials and Methods. Two female adult patients with symptoms of TMD who agreed to participate in the study were selected for this study. Immortalized human juvenile costal chondrocyte C-28/I2 was grown to 80% confluency and synovial fluids from two patients were added respectively to culture media for 24 hours at the concentration of 100ng/10ml. Confocal laser scanning microscope (CLSM) was used to examine changes of intracellular calcium concentration ([$Ca^{2+}$]i). RT-PCR was performed to identify the expression profile of IL-1${\alpha}$, iNOS, COX-2. Results. Increased [$Ca^{2+}$]i was observed in chondrocytes subjected to inflamed synovial fluid compared to control cultures and in respective cultures exposed to inflamed synovial fluids from each patient, IL-1${\beta}$, COX-2 mRNA were detected. However, in neither case iNOS mRNA was expressed. IL-1${\alpha}$, COX-2, and iNOS mRNA were expressed in control culture. Conclusion. Our results show that immortalized chondrocytes cultured with inflamed synovial fluids from patients diagnosed as disc displacement without reduction and limitation in mouth opening showed increased calcium concentration and expression of COX-2 while inhibiting the production of iNOS, which in turn could adversely affect the chondrocytes in at least short term by hindering physiologic role of NO against inflammatory cascades. These findings suggest that inflamed synovial fluid may differentially regulate the transcriptomes of relevant inflammatory mediators, especially iNOS/COX-2 axis in chondrocytes through adjusting calcium transients.

• Journal of Sensor Science and Technology
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• v.23 no.6
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• pp.368-376
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• 2014

In order to measure the segmental impedance of the body, a bioelectrical impedance measurement system (BIMS) using multi-frequency applying method and two-electrode method was implemented in this study. The BIMS was composed of constant current source, automatic gain control, and multi-frequency generation units. Three experiments were performed using the BIMS and a commercial impedance analyzer (CIA). First, in order to evaluate the performance of the BIMS, four RC circuits connected with a resistor and capacitor in serial and/or parallel were composed. Bioelectrical impedance (BI) was measured by applying multi-frequencies -5, 10, 50, 100, 150, 200, 300, 400, and 500 KHz - to each circuit. BI values measured by the BIMS were in good agreement with those obtained by the CIA for four RC circuits. Second, after measuring BI at each frequency by applying multi-frequency to the left and right forearm and the popliteal region of the body, BI values measured by the BIMS were compared to those acquired by the CIA. Third, when the distance between electrodes was changed to 1, 3, 5, 7, 9, 11, 13, and 15 cm, BI by the BIMS was also compared to BI from the CIA. In addition, BI of extracellular fluid (ECF) was measured at each frequency ranging from 10 to 500 KHz. BI of intracellular fluid (ICF) was calculated by subtracting BI of ECF measured at 500 kHZ from BI measured at seven frequencies ranging from 50 to 500 KHz. BI of ICF and ECF decreased as the frequency increased. BI of ICF sharply decreased at frequencies above 300 KHz.

• Journal of Sensor Science and Technology
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• v.25 no.1
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• pp.1-7
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• 2016

Bioelectrical impedance (BI) at popliteal regions was measured using a bioelectrical impedance measurement system (BIMS), which employs the multi-frequency and the two-electrode method. Experiments were performed as follows. First, a constant AC current of $800{\mu}A$ was applied to the popliteal regions (left and right) and the BI was measured at eight different frequencies from 10 to 500 kHz. When the applied frequency greater than 50 kHz was applied to human's popliteal regions, the BI was decreased significantly. Logarithmic plot of impedance vs. frequency indicated two different mechanisms in the impedance phenomena before and after 50 kHz. Second, the relationship between resistance and reactance was obtained with respect to the applied frequency using BI (resistance and reactance) acquired from the popliteal regions. The phase angle (PA) was found to be strongly dependent on frequency. At 50 kHz, the PA at the right popliteal region was $7.8^{\circ}$ slightly larger than $7.6^{\circ}$ at the left popliteal region. Third, BI values of extracellular fluid (ECF) and intracellular fluid (ICF) were calculated using BIMS. At 10 kHz, the BI values of ECF at the left and right popliteal regions were $1664.14{\Omega}$ and $1614.08{\Omega}$, respectively. The BI values of ECF and ICF decreased sharply in the frequency range of 10 to 50 kHz, and gradually decreased up to 500 kHz. Logarithmic plot of BI vs. frequency shows that the BI of ICF decreased noticeably at high frequency above 300 kHz because of a large decrease in the capacitance of the cell membrane.

• Korean Journal of Acupuncture
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• v.29 no.1
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• pp.71-81
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• 2012

Objectives : The purpose of this paper was to suggest new diagnostic method that was to supersede the estimation of electrical properties at acupoints. Thus, we developed the multi- frequencies bioelectrical impedance measurement system so as to analyze the state of bio-ions in body fluid as body compositions, not skin impedance at acupoint. Methods : At low frequency, the current does not penetrate the cell membrane and at high frequency, the current passes through both intracellular and extracellular fluid because of the decreas of cell membrane impedance. To confirm the reflection of composition in extracellular fluid or intracellular fluid of segment such as acupoint, the system was developed to detect the acupoint potential between adjacent two points in the area of LU3, LU4 and LU9 using 5,50 and 200KHz. Results : The detected acupoint potential has been decreased according to elevation of frequency. As a result of correlation of left/right identical acupoint, we observed a high correlation of three types of acupoint potential at multi-frequencies. Moreover, we observed the low correlation at 5KHz, and that was a significant factor to be considered as unbalanced relationship of identical acupoints. Conclusions : On the basis of meridian theoretical point of view, we may infer the acupoint's physiological composition using the multi-frequencies bioelectrical impedance measurement system.