• The Korean Journal of Physiology and Pharmacology
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• v.3 no.2
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• pp.231-236
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• 1999

This study was performed to examine 1) Whether hypothermic cardiac arrest produces myocardial HSP72 expression; 2) And if, whether it serves to protect the heart against the subsequent hypothermic arrest. In the present study, neonatal rats were placed in an icebath to induce hypothermia. To determine whether hypothermic cardiac arrest produces myocardial HSP72, experimental animals were subjected to 10-min hypothermic insult before the extraction of the heart. The intervals between the insult and extraction were 1 (1 HR), 4 (4 HR), 8 (8 HR), 24 (24 HR) or 72 (72HR) hours. A minimal amount of HSP72 was detected in control, 1 HR and 72 HR groups. In contrast, 8 HR and 24 HR groups showed a significant level of HSP72 expressions. To assess the cardioprotective effect of HSP72 against hypothermic cardiac arrest, we compared the proportion of recovery from the arrest between control and preconditioned (PREC) animals. Control animals were subjected to 20-min hypothermic insult, while PREC group was preconditioned by 10-min hypothermic insult 8 hours before the 20-min test hypothermic insult. Resuscitation rate from cardiac arrest induced by the 20-min hypothermic insult in PREC group was significantly higher than that in controls. These results suggest that the cardioprotective effect of hypothermic preconditioning is associated with an increase in HSP72 expression.

• The Korean Journal of Physiology
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• v.20 no.2
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• pp.175-183
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• 1986

Since it was proposed that vanadate may be an ‘ideal endogenous regulator of the $Na^+,\;K^+-ATPase$ activity (Cantley et at, 1979), vanadate has been a subject of intensive research and a variety of its physiological effects have been described (Nechay, 1984). In isolated guinea pig heart muscle vanadate shows a positive inotropic effect on ventricular muscle, while it induces a negative inotropic effect on atrial muscle. But its underlying mechanism has not been elucidated so far. Therefore, in this study the flux rates of calcium ion into and from guinea pig heart muscle were measured to throw some light on the underlying mechanism, because those rates have been known to be closely related to the cardiac contractility and the results are summarized as follows: 1) Calcium efflux rates from the intracellular $Ca^{++}$ pool (compartment 4) of both guinea pig left atrium and right ventricle were significantly reduced by vanadate and their pool sizes were significantly increased by vanadate. 2) The magnitude of calcium influx into left atrium was reduced by vanadate, While the magnitude of calcium influx into right ventricle was not affected by vanadate. From these results, it may be concluded that the positive inotropic effect of vanadate on the ventricular muscle was due to a reduced efflux rate of calcium ion and its negative inotropic effect on atrial muscle was resulted from a reduced influx of calcium ion.

• Journal of Ginseng Research
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• v.37 no.3
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• pp.273-282
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• 2013

The present study was designed to investigate the cardioprotective effects of Korean Red Ginseng extract (KRG) on isoproterenol (ISO)-induced cardiac injury in rats, particularly in regards to electrocardiographic changes, hemodynamics, cardiac function, serum cardiac enzymes, components of the myocardial antioxidant defense system, as well as inflammatory markers and histopathological changes in heart tissue. ISO (150 mg/kg, subcutaneous, two doses administered at 24-hour intervals) treatment induced significant decreases in P waves and QRS complexes (p<0.01), as well as a significant increase in ST segments. Moreover, ISO-treated rats exhibited decreases in left-ventricular systolic pressure, maximal rate of developed left ventricular pressure ($+dP/dt_{max}$) and minimal rate of developed left ventricular pressure ($-dP/dt_{max}$), in addition to significant increases in lactate dehydrogenase, aspartate transaminase, alanine transaminase and creatine kinase activity. Heart rate, however, was not significantly altered. And the activities of superoxide dismutase, catalase and glutathione peroxidase were decreased, whereas the activity of malondialdehyde was increased in the ISO-treated group. ISO-treated group also showed increased caspase-3 level, release of inflammatory markers and neutrophil infiltration in heart tissue. KRG pretreatment (250 and 500 mg/kg, respectively) significantly ameliorated almost all of the parameters of heart failure and myocardial injury induced by ISO. The protective effect of KRG on ISO-induced cardiac injury was further confirmed by histopathological study. In this regard, ISO treatment induced fewer morphological changes in rats pretreated with 250 or 500 mg/kg of KRG. Compared with the control group, all indexes in rats administered KRG (500 mg/kg) alone were unaltered (p>0.05). Our results suggest that KRG significantly protects against cardiac injury and ISO-induced cardiac infarction by bolstering antioxidant action in myocardial tissue.

• CELLMED
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• v.3 no.2
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• pp.13.1-13.6
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• 2013

The objective of the current study was to find out the effect of Integrated Amrita Meditation Technique (IAM) on blood pressure (BP), heart rate (HR), respiratory rate (RR) and IgA. One hundred and fifty subjects were randomized into three groups IAM, Progressive Muscle Relaxation (PMR) and Control. Baseline values were collected before giving the training for all the subjects and the IAM and PMR groups were given training in the respective techniques. BP, HR, RR and IgA were recorded manually at 0 h, 48 h, 2 months and 8 months after the first visit. HR was found to be reduced in the IAM group 48 h onwards and the fall sustained till 8 months (p < 0.05). IAM group showed significant drop when compared to the PMR group and control group in all the subsequent visits (p < 0.05). RR decreased significantly in the IAM group in the third and fourth visits (p < 0.05). RR of IAM showed significant decrease when compared to PMR and control from the third visit onwards. IgA showed significant increase in comparison with PMR and control in the third and fourth visits. BP did not show any difference in any of the visits. There was subject dropout from randomization to completion of the study, in all the three groups. The significant decrease in HR and RR and increase in IgA in the IAM group when compared to the PMR and control group shows the efficacy of the technique in reducing the physiological stress indicators for up to 8 months.

• Journal of Ginseng Research
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• v.34 no.2
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• pp.132-137
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• 2010

Lead (Pb) is a metal that is generally considered to be toxic to the cardiovascular system. Pb-exposed animals display the evidence of increased oxidative stress and hypertension. The current study was designed to examine whether Korean red ginseng (KRG) has protective effects against Pb-induced hypertension and oxidative stress in Pb-exposed rats. Male Sprague-Dawley rats were randomly assigned to Pb exposure or control groups. KRG was administered in drinking water at a concentration of 100 mg/kg/day; the control group received plain drinking water. Animals in the Pb-exposed groups were provided with drinking water containing 100 ppm Pb acetate for 12 weeks. Blood pressure, plasma glutathione, blood Pb concentration, and hematologic data, such as red blood cell quantity, were determined. Pb poisoning was assessed by measuring the blood Pb concentration. Pb exposure (100 ppm) for 12 weeks resulted in a marked rise in systolic blood pressure and blood Pb concentration, as well as a significant reduction in plasma glutathione levels and red blood cell quantity. Other measurements, such as heart rate, body weight, and white blood cell quantity, were unchanged. Treatment with KRG significantly lowered blood pressure, raised plasma glutathione and increased red blood cell numbers in Pb-exposed animals; it also had no effect on heart rate, body weight, or white blood cell quantity. However, the elevated blood Pb concentration was not reduced by treatment with KRG (100 mg/kg). Taken together, these data indicate that treatment with KRG in Pb-exposed animals can reduce oxidative stress and lower blood pressure, suggesting that KRG might be protective against Pb-exposed hypertension and oxidative stress.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.1
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• pp.49-59
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• 2023

Metabolic syndrome (MetS) involves multi-factorial conditions linked to an elevated risk of type 2 diabetes mellitus and cardiovascular disease. Pre-metabolic syndrome (pre-MetS) possesses two MetS components but does not meet the MetS diagnostic criteria. Although cardiac autonomic derangements are evident in MetS, there is little information on their status in pre-MetS subjects. In this study, we sought to examine cardiac autonomic functions in pre-MetS and to determine which MetS component is more responsible for impaired cardiac autonomic functions. A total of 182 subjects were recruited and divided into healthy controls (n=89) and pre-MetS subjects (n=93) based on inclusion and exclusion criteria. We performed biochemical profiles on fasting blood samples to detect pre-MetS. Using standardized protocols, we evaluated anthropometric data, body composition, baroreflex sensitivity (BRS), heart rate variability (HRV), and autonomic function tests (AFTs). We further examined these parameters in pre-MetS subjects for each MetS component. Compared to healthy controls, we observed a significant cardiac autonomic dysfunction (CAD) through reduced BRS, lower overall HRV, and altered AFT parameters in pre-MetS subjects, accompanied by markedly varied anthropometric, clinical and biochemical parameters. Furthermore, all examined BRS, HRV, and AFT parameters exhibited an abnormal trend and significant correlation toward hyperglycemia. This study demonstrates CAD in pre-MetS subjects with reduced BRS, lower overall HRV, and altered AFT parameters. Hyperglycemia was considered an independent determinant of alterations in all the examined BRS, HRV, and AFT parameters. Thus, hyperglycemia may contribute to CAD in pre-MetS subjects before progressing to MetS.

• The Korean Journal of Physiology
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• v.7 no.2
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• pp.31-37
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• 1973

The effects of ethanol extacts of aconite root (Aconitum koreanum) on mean arterial pressure, heart rate, pulse pressure, and respiration were investigated and also studied the effect on electrical activation of the hypothalamus in cats. From the present experiment the following results were obtained. 1) On administering 5 mg or 10 mg aconite extracts per kg of body weight, the mean arterial blood pressure declined markedly possibly as the result of negative inotropic and chronotropic effects of aconite. 2) From the enhanced pressor responses to intravenously injected epinephrine, the existance of vasodilatory effect of the aconite was suggested. 3) After administration of aconite extract, no significant differences were observed in the presser responses to carotid occlusion and to electrical stimulation of the hypothalamus. It is, therefore, concluded that the aconite extract exerts no significant effect on the excitability of hypothalamus as well as medullary cardiovascular center of cats. 4) After administration of $5{\sim}10$ mg/kg aconite extracts, respiratory rate was increased while depth of respiration decreased. On the otherhand, respiratory rate was markedly decreased by injection of 20 mg/kg aconite into animal.

• The Korean Journal of Physiology
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• v.6 no.2
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• pp.31-37
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• 1972

The right cervical vagus nerve was electrically stimulated for 30 sec, and 30 minutes recording cardiac rate responses and electrocardiogram. The main purposes of the present experiment are to determine effect of stimulation frequency on the maintenance of cardiac rate responses and to determine recovery time of sinus rhythm after asystole period followed by idioventricular rhythm during prolonged electrical stimulation of the vagus, and the optimal stimulation parameters for vagal stimulation were studied as well. The results obtained are summarized as follows: 1. The maximum negative chrontropic responses were obtained with the following ranges of electrical parameters. Intensity: 3V-7V, Frequency: 20/sec-60/sec, and pulse duration: 5 msec-20 msec. 2. Compared with the responses from sympathetic effectors, cardiac rate responses to electrical stimulation of vagus nerve were well maintained with all stimulation frequencies. 3. At all stimulation frequencies except 20/sec, sinus node started to take over primary pacemaker activity when cardiac rates were restored to about 38-40/min. 4. It was indicated that upper limit of idioventricular rhythm does not exceed 38-40/min. 5. With the stimulation parameter set of 20/sec-5 msec-3 V, sinus rhythm did not appear during 30 minutes of stimulation period. Therefore, this electrical parameter set appears to be optimal for elicitation of prolonged and maximum cardiac rate responses by vagal stimulation.

• The Korean Journal of Physiology
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• v.16 no.1
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• pp.41-50
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• 1982

The effects of $NaHCO_3$ on the electrocardiogram of rats were studied in the induced hyperkalemia. The subjects were divided into 4 groups: the group 1 was normal control and the data on this normal control had teen obtained from the following three groups before administration of KCl or $NaHCO_3$, the group 2 (KCl) was administered 40 ml per kg body weight of the 10 per cent KCl solution, the group 3 $(NaHCO_3)$ was administered 40 ml per kg body weight of the 10 per cent $NaHCO_3$ solution, and the group 4 $(KCl+NaHCO_3)$ was received 10 per cent KCl, which was followed by administration of 10 per cent $NaHCO_3$ at one and half hours later. In KCl, the heart rate was decreased rapidly, and then maintained its level, later rapid decreasing heart rate was followed by the cardiac stand still. The mean electrical axis of QRS complex became progressively deviated to the left. The amplitude of T wave was increased transiently but was not changed thereafter. There was prolongation of the P-Q interval and the Q-T interval at the beginning and then they were shortened. In $NaHCO_3$, the heart rate was decreased rapidly at the beginning, later showed a tendency of recovery. The mean electrical axis of QRS was not changed initially, but later became deviated to the left. The amplitude of T wave was not changed. There was prolongation of the P-Q interval and the Q-T interval at the beginning and then they were shortened. In $KCl+NaHCO_3$, there were a tendency of recovery of both the amplitude of the T wave and the electrical axis of the QRS complex after administration of $NaHCO_3$ but the heart rate was not recovered. There was prolonged P-Q interval, but the Q-T interval was relatively unchanged.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.4
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• pp.283-289
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• 2013

This study was designed to evaluate the protective effect of Korean red ginseng (KRG) against ischemia/reperfusion (I/R) injury in isolated guinea pig heart. KRG has been shown to possess various ginsenosides, which are the major components of Panax ginseng. These components are known naturally occurring compounds with beneficial effects and free radical scavenging activity. The heart was induced to ischemia for 60 min, followed by 120 min reperfusion. The hearts were randomly allocated into five groups (n=8 for each group): normal control (N/C), KRG control, I/R control, 250 mg/kg KRG group and 500 mg/kg KRG group. KRG significantly increased hemodynamics parameters such as aortic flow, coronary flow and cardiac output. Moreover, KRG significantly increased left ventricular systolic pressure (LVSP), the maximal rate of contraction (+dP/$dt_{max}$) and maximal rate of relaxation (-dP/$dt_{max}$). Also, treatment of KRG ameliorated electrocardiographic index such as the QRS, QT and RR intervals. Moreover, KRG significantly suppressed the lactate dehydrogenase, creatine kinase-MB fraction and cardiac troponin I and ameliorated the oxidative stress markers such as malondialdehyde and glutathione. KRG was standardized through ultra performance liquid chromatograph analysis for its major ginsenosides. Taken together, KRG has been shown to prevent cardiac injury by normalizing the biochemical and oxidative stress.