• YAKHAK HOEJI
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• v.29 no.6
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• pp.367-374
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• 1985

The age-related changes of monoamine contents and monoamine oxidase (MAO) activities in the whole brain and blood pressures were measured and compared every week during the ages of 5 weeks to 12 weeks in two types of animals; (1) spontaneously hypertensive rats (SHR) and (2) normotensive Sprague-Dawley rats (NR). Blood pressures in SHR began to rise at the ages of 7 or 8 weeks and were significantly higher thereafter than in NR. Abnormally low MAO activities in the brain of SHR were detected from the ages of 8 weeks. Comparisons were also made between brain monoamine-norepinephrine, dopamine and 5-hydroxytrytamine contents of SHR and those of NR at the same ages throughout the test period. In SHR, none of those monoamine values was consistently higher or lower than in NR during the test period. Protein contents of the brain between SHR and NR were not significantly different at any ages. These observations suggest that the abnormally low MAO activities in SHR brain may be one of the underlying neurological factors for the susceptibilities to hypertension and the deficit of MAO activities may be due to the changes in properties rather than in amount of this enzyme.

• Archives of Pharmacal Research
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• v.16 no.4
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• pp.305-311
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• 1993

$Na^+,K^+$-ATPase activity, $Na^+$-dependent phosphorylation, and $[^3H]$ ouabain binding in sarcolemma prepared from 4 week old spontaneously hypertensive rat(SHR) ventricles were compared to the same parameters in sarcolemma from age matched nomotensive Wister-Kyoto (WKY) rat ventricles to examine whether the reduced myocardial $Na^+$-pump activity in SHR is an inherited enzymatic defect or a second phenomenon due to sustained hypertension. The total body weights, ventricular weights, and blood pressures were the same for SHR and WKY. No significant differences in sarcolemmal protein content and protein recovery were noted between the two groups. Sarcolemma isolated from SHR ventricles showed significantly less $Na^+,K^+$-ATPase activity ande number of phosphorylation sites when compared to sarcolemma from the WKY ventricles. Equilibrium binding of $[^3H]$ouabain and the tumover number of myocardial $Na^+,K^+$-ATPase, however, were the same for both groups. These reults indicate that the low affinity $(\alpha,\;or\;\alpha^1)\;\alpha$ isoform is the same in ventricles of SHR and WKY. The reduced amount of isoform of the $Na^+,K^+$-ATPase inprehypetensive SHR ventricles may play some role in the development of hypertension.

• The Journal of Internal Korean Medicine
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• v.27 no.3
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• pp.617-628
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• 2006

This experiment was performed to determine the effects of Kamibangpungtongsungsan on hypertension in spontaneous hypertensive rats fed a hyperlipidemic diet (H-SHR). The results are summarized as follows : 1. Kamibangpungtongsungsan significantly decreased the blood pressure and pulse of rats in H-SHR. 2. Kamibangpungtongsungsan significantly decreased the levels of Aldosterone in H-SHR. 3. Kamibangpungtongsungsan significantly decreased the levels of dopamine and epinephrine in H-SHR, but did not significantly reduce the levels of norepinephrine, in H-SHR. 4. Kamibangpungtongsungsan did not significantly reduce the levels of electrolytes in H-SHR. 5. Kamibangpungtongsungsan significantly decreased the TNF-$\alpha$ and IL-6 levels in H-SHR but the IL-10 level increase no significant. These results suggest that the Kamibangpungtongsungsan might be usefully applied for the treatment of hypertension with hyperlipidemia.

• Food Science of Animal Resources
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• v.44 no.1
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• pp.178-188
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• 2024

The aim of this study is to investigate whether milk fermented by Lactiplantibacillus plantarum K79, which exhibits angiotensin-converting enzyme inhibitory activity, has an effect on lowering the blood pressure of hypertensive rats and to investigate biomarker changes in their blood. Experimental group: normal group (NG, Wistar-Kyoto rats): distilled water, control group [NCG, spontaneously hypertensive rats (SHR)]: distilled water, high treatment group (HTG, SHR): 500 mg/kg/day, medium treatment group (SHR): 335 mg/kg/day, low treatment group (SHR): 170 mg/kg/day, positive control group (PCG, SHR): Enalapril, 10 mg/kg/day. The experimental animals used in this study were divided into groups composed of 8 animals. In terms of weight change, a significant difference was observed between the NG and the SHR group, but there was no significant difference between the SHR group. After 8 wk of feeding, blood pressure was lowered more significantly in the HTG (209.9±13.3 mmHg) than in the NCG (230.8±7.3 mmHg). The treatment group has an effect of lowering blood pressure by significantly suppressing blood pressure-related biomarker protein expression than NG. The results obtained can be used as an antihypertensive material in a variety of food raw materials.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.703-706
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• 2005

The purpose of this study is to investigate the combined effect of L-arginine supplementation and regular physical exercise on HR, BP, eNOS and Macrophage activation using SHR. To examine the differences among HR, BP, eNOS, and Macrophage activity levels, normotensive Wistar-Kyoto rats were used as a control. Thirty two male rats (six weeks old) were divided into four groups; eight WKY control (WKYC), eight SHR control (SHRC), eight SHR supplemented with L-arginine (SHRA), and eight SHR trained and supplemented with L-arginine (SHRTA). Obtained results were as follows : In the heart and blood pressure, there was significant differences anong the four group (p<.05) compare to SHRC. In the eNOS levels, there was significant differences among the four groups (p<.05) compare to SHRC. In the macrophage activity, there was significant differences among the four groups (p<.05) compare to SHRC. In conclusion, For the SHRC group, the level of eNOS is higher than that of WKYC, and we can expect tissue damage caused by toxic free radical. However, this can be stabilized by the L-arginine supplementation and regular physical training. we can also conclude regular aerobic training decrease cardiovascular stress caused by stabled macrophage activity. Therefore, we can trace it is the effect of training in SHR.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.579-582
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• 2001

Twenty one Spontaneously Hypertensive Rats(SHR) that were 4- to 21-month-old were examined histopathologically and serologically during a routine health monitoring of the rat colony. The results of the enzyme linked immunosorbent assay(ELISA) for murine pathogens demonstrated that 14 of 21 SHR rats had antibodies to Mycoplasma pulmonis. Histopathologically, the mycoplasma positive SHR rats were observed to have the typical pulmonary lesions which are characterized by the hyperplasia of the lymphoid tissue around the bronchi, bronchioles and vessels. Based on the histopathological findings and serological results, this case was diagnosed as a murine mycoplasmosis of SHR rats.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.6
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• pp.621-628
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• 2016

Hypertension can be caused by various factors while the predominant causes include increase in body fluid volume and resistance in the circulatory system that elevate the blood pressure. Consumption of probiotics has been proven to attenuate hypertension; however, the effect is much strain-dependent. In this study, a newly isolated Lactobacillus casei (Lb. casei ) strain C1 was investigated for its antihypertensive properties in spontaneously hypertensive rats (SHR). Lactic acid bacteria (LAB) suspension of 11 log colony-forming unit (CFU) was given to SHR (SHR+LAB, n=8), and phosphate buffer saline (PBS) was given as a control in SHR (SHR, n=8) and in Wistar rats as sham (WIS, n=8). The treatment was given via oral gavage for 8 weeks. The results showed that the weekly systolic blood pressure (SBP), mean arterial pressure (MAP), diastolic blood pressure (DBP) and aortic reactivity function were remarkably improved after 8 weeks of bacterial administration in SHR+LAB. These effects were mostly attributed by restoration of wall tension and tensile stress following the bacterial treatment. Although not statistically significant, the level of malondialdehye (MDA) in SHR+LAB serum was found declining. Increased levels of glutathione (GSH) and nitric oxide (NO) in SHR+LAB serum suggested that the bacterium exerted vascular protection through antioxidative functions and relatively high NO level that induced vasodilation. Collectively, Lb. casei strain C1 is a promising alternative for hypertension improvement.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.291-296
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• 1987

There have been reports on the aberration of the control mechanisms of the blood pressure, hormone secretion, and renal functions in spontaneously hypertensive rats (SHR). However, the contribution of the renin-angiotensin system in the maintenance of high blood pressure in SHR is still controversial. Recently, it has been reported that the negative feedback short loop control mechanism of the renin-angiotensin system may be changed in SHR. In the present experiment, it was attempted to explore the possible alterations in the effect of arginine vasopressin (AVP) on the renal function in SHR. Experiments have been done in anesthetized SHR as well as in normotensive Wistar and Sprague-Dawley rats as control groups. Pharmacologic doses of AVP (10-13 mU/rat/10 min) decreased urine volume, excreted amount of creatinine and para-amino-hippuric acid. No differences in these parameters was observed between normotensive and hypertensive rats. AVP increased sodium and potassium excretion, but the responses in SHR were suppressed as compared with normotensive rats. Intravenous infusion of AVP also increased blood pressure in normotensive and hypertensive rats and a vasopressor effect of AVP was attenuated in SHR. There was a positive correlation between the changes in blood pressure and excreted amount of sodium during AVP infusion. These data suggest that the attenuated natriuretic effect of intravenous infusion of AVP may be due to a difference in renal tubular responsiveness to AVP but not due to a difference in vasopressor responsiveness.

• Biomolecules & Therapeutics
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• v.8 no.2
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• pp.194-198
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• 2000

Taurine, 2-aminoethanesulfonic acid is widely distributed in animal tissues and has a variety of bio-logical activities. A recent worldwide study demonstrated beneficial effects of taurine on aging and age-associated disorders. In general, taurine levels in the brain decease when an animal is subjected to pathologic conditions such as ischemia-anoxia and seizure. But the taurine levles tend to increase in the brain in hypertensive state. In the present study, the blood-brain barrier (BBB) transport of [$^3$H]taurine was compared between spontaneously hypertensive rats (SHR) and normotensive Sprague-Dawley rats (SD) using intravenous injection technique in vivo. We also obtained pharmacokinetic parameters of plasma volume maker, [$^{14}$ C] sucrose and [$^3$H]taurine after inject to rats simulatenously. BBB permeability surface area product (PS) value of [$^3$H]taurine in SHR (16$\pm$2.9$\times$10$^{-3}$ ml/min/g) was significantly higher than that in SD (7.4$\pm$0.8$\times$10$^{-3}$ ml/min/g). There is also significant difference for brain uptake of [$^3$H]taurine between SHR (0.195$\pm$0.031%ID/g) and SD (0.058$\pm$0.003% ID/g). This is due to difference of area under the plasma concentration-time curve (AUC) and that of total clearance (Class) between SHR and SD. No significant difference was indicated from other organ uptakes such as lung, heart, liver SHR and SD. But also kidney uptake was much higher in SHR. In conclusion, [$^3$H]taurine in plasma was slowly eliminated in SHR than in SD and uptake of [$^3$H]taurine in SHR is much higher than that of SD. This results suggest increased taurine level in the brain in hypertension state have an any effect on the brain uptake of taurine.

• YAKHAK HOEJI
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• v.33 no.6
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• pp.333-338
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• 1989

It has been postulated that abnormal characteristics of central noradrenergic nervous system has been implicated in the development and maintenance of hypertension in several modes of experimental hypertension including spontaneously hypertensive rats (SHR). In the present study, we attempt to determine if abnormal characteristics of central noradrenergic nervous system in SHR is caused by genetic factors or hypertensive phenomena by evaluating the changes of central adrenoceptors after long-term treatment of clonidine. Animals were divided into three groups; (1) 14 week-old SHR; (2) age-matched normotensive Wistar rats (NW); (3) DOCA-Salt induced hypertensive rats (DS). Clonidine (100 ug/kg) or vehicle was injected intraperitonealy twice a day for 15 days. Changes of ${\alpha}_1-$ and ${\alpha}_2-receptor$ desities following clonidine treatment were determiend in frontal corte, medulla oblongata and hypothalamus using 3H-WB4101 and 3H-clonidine, respectively. Densities of ${\alpha}_1$ and ${\alpha}_2-receptors$ following clonidine treatment were not changed in frontal cortex and medulla oblongate of SHR as well as DS, but increased in frontal cortex of NW and decreased in medulla oblongata of NW. On the other hand, densities of ${\alpha}_1-receptors$ were increased and densities of ${\alpha}_2-receptors$ were not changed in hypothalamus of SHR but densities of ${\alpha}_1-$ and ${\alpha}_2-receptors$ were decreased in hypothalamus of DS as well as NW. These results suggest that such differences in frontal cortex and medulla oblongata of SHR may be results of hypertensive phenomena whereas those in hypothalamus may be relevant to genetic factors of SHR.