• The Korea Journal of Herbology
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• v.26 no.1
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• pp.75-80
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• 2011

Objectives : The aim of the present study is to investigate the hypotensive effect of Samhwangsasim-tang (SHSST), Samigangap-tang (SMGAT) and Bangtan-tang (BTT) in stroke-prone spontaneously hypertensive rats (SHR-SP). Methods : SHR-SP rats were treated with SHSST, SMGAT and BTT at dose of 200 mg/kg/day orally for 5 weeks, respectively. Results : Treatment SHR-SP rats with SMGAT significantly lowered blood pressure but not in the SHSST or BTT treat groups. On the other hand, SHSST, SMGAT and BTT ameliorated endothelium-dependent and independent vascular relaxation in the phenylephrine-precontracted aorta and carotid artery, respectively. Conclusions : These results indicated that SMGAT has an antihypertensive effect and SHSST, SMGAT and BTT improve vascular function in stroke-prone hypertensive rat model, respectively.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.545-550
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• 2010

The effects of casein hydrolysate on blood pressure (BP) and serum lipid profiles were investigated in spontaneously hypertensive rats (SHR). Twenty-four 6-wk old male SHRs were assigned to 3 groups in a completely randomized design. Experimental groups were as follow: control, market milk group (MLG) and casein hydrolysate group (CHG). Reference blood pressure (RBP) showed average $198.94{\pm}1.46mmHg$. Blood pressure (BP) of CHG reduced 24 mmHg after 2 wk of treatment, but these increased after 3 wk. BP of CHG was significantly lower than BP of Control in experimental time (p<0.05). Serum lipid profiles were not differ significantly among groups (p<0.05). These data suggest that casein hydrolysate may beneficially improvement of blood pressure level in SHR.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.7-13
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• 2004

Severe hypertension (>180 mmHg) develops in spontaneously hypertensive rats (SHR) after 12 wk-old; however, it is not clear whether what kinds of molecular mechanism leads to altered cardiac performance following developmental stages in SHR. Also, although the effect of calcineurin (Cn) to promote cardiomyocyte hypertrophy in vivo and in vitro is established, its overall necessity as a hypertrophic mediator is currently an area of ongoing debate. Thus, we have examined i) body weight and blood pressure, ii) differences of expression and distribution of signaling molecules such as Cn, protein kinase B/Akt (PKB/Akt), and extracellular signal-regulated kinase (ERK) between SHR and their age-matched control Wistar-Kyoto (WKY) rats following developmental stages. In 16 wk-old SHR compared with WKY, 2-dimentional echocardiography showed cardiac enlargement and hypertrophy of left ventricle, significantly. Taken together, we suggest that Cn is associated with hereditary cardiac hypertrophy, the process being related to the molecular signaling mechanisms involving PKB/Akt and ERK.

• IMMUNE NETWORK
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• v.9 no.3
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• pp.106-113
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• 2009

Background: We previously demonstrated remarkable differences in the expression of IL-8/CXCL8 in aortic tissues and vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) compared to VSMC from normotensive Wistar-Kyoto rats (WKY). In the present study, we investigated the direct effect of IL-8/CXCL8 on expression of 12-lipoxygenase (LO), a hypertensive modulator, in SHR VSMC. Methods: Cultured aortic VSMC from SHR and WKY were used. Expression of 12-LO mRNA was determined by real-time polymerase chain reaction. Phosphorlyation of ERK1/2 and production of 12-LO and angiotensin II subtype 1 ($AT_1$) receptor were assessed by Western blots. IL-8/CXCL8-stimulated DNA synthesis was determined by measuring incorporation of [$^3H$]-thymidine. And effect of IL-8/CXCL8 on vascular tone was determined by phenylephrine-induced contraction of thoracic aortic rings. Results: Treatment with IL-8/CXCL8 greatly increased 12-LO mRNA expression and protein production compared to treatment with angiotensin II. IL-8/CXCL8 also increased the expression of the $AT_1$ receptor. The increase in 12-LO induced by IL-8/CXCL8 was inhibited by treatment with an $AT_1$ receptor antagonist. The induction of 12-LO mRNA production and the proliferation of SHR VSMC by IL-8/CXCL8 was mediated by the ERK pathway. The proliferation of SHR VSMC and the vascular contraction in the thoracic aortic ring, both of which were induced by IL-8/CXCL8, were inhibited by baicalein, a 12-LO inhibitor. Conclusion: These results suggest that the potential role of IL-8/CXCL8 in hypertensive processes is likely mediated through the 12-LO pathway.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2007.11a
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• pp.236.2-236.2
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• 2007

• Journal of Nutrition and Health
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• v.29 no.10
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• pp.1087-1095
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• 1996

The study was carried out to investigate a new type of functional foods with hypotensive effect which is critical in the prevention and treatment of hypertension and related circulatory diseases. The experimental diets(A, B, C) were prepared from plant based ingredients such as buckwheat, potato, perilla seed with different ratios formulated as an edible form appropriate for human consumption according to AIN-77 standard. Control group(D) was fed commercial rat chow. Twety-four 15-week-old SDR(Sprague Dawley rats) and twenty-four 20-week-old SHR(spontaneously hypertensive rats), weighing 200g respectively, were assigned to 4 treatments of 6 rats each in a completely randomized design. Blood pressure was measured at 7 day interval by tail-cuff sphygmomanometer using an IITC cuff pump and amplifier. The growth rates of both SHR and SDR were not statistically different in comparions with the control except those of diet B and C in SDR and SHR, respectively(p<0.05). When exprimental diets were fed, systolic blood pressure of SDR and SHR at day 28 had been lowered by 17-20 mmHg(ave. of 19.6mmHg for both strains) compared with the reference pressure at day 0. The levels of HDL-cholesterol were increased, while the levels of LDL-cholesterol consistently decreased in both strains when experimental diets were fed(p<.05). Plasma total cholesterol levels were not different among treatments. Plasma triglyceride levels were higher in control diet(commercial rat chow) due to two times higher fat content of control diet itself(p<.05). Atherogenic indices were lower compared to those of control when the experimental diets were fed in both strains (p,.05). The results suggest that the antihypertensive diets mainly consisting of plant-based ingredients may possibly effective in relieving hypertension as well as circulatory diseases.

• The Korean Journal of Physiology
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• v.22 no.2
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• pp.295-305
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• 1988

It has been well known that the renal cortical blood flow rate was much higher than that of the medulla and the renal blood flow distribution was affected by hemorrhage, volume expansion or salt-loading. The existance of the heterogeneities of glomerular filtration rate and nephron has also been reported. In order to understand the regulations and physiological roles of the heterogeneities, studies on the intrarenal renin-angiotensin system have been focused. Although it is well known that the granularity of iuxtaglomerular cells and renal renin content are more marked in superficial than in the deep glomeruli, their physiological significance is not quite clear. This study was therefore undertaken to clarify changes in renin response and isoelectric ronin profile to TMB-8 in outer, mid and inner cotices of normotensive and hypertensive rats. The basal rate of renin release was highest in outer cortex of Sprague-Dawley rat (SDR), Wistar rat (WR) and spontaneously hypertensive rat (SHR). The basal renin release from outer and inner cortex of SHR was significantly lower than that from those of SDR. The reponse of renin release to TM8-8 was highest in mid cortex and the increase of renin release in response to TMB-8 from inner cortex of SDR was significantly higher than that in SHR. In dehydrated rats, the basal renin release from renal cortical slices of SDR was increased but that from WR and SHR was not. The response of renin release to TMB-8 from mid and inner cortex of dehydrated WR tended to increase. In dehyrated SHR, increase of renin release from inner cortex was significantly higher than that in euhydrated SHR. No significant differences in the isoelectric renin profile were found both in different cortical areas and strains. In dehydrated rats, the percentage of renin form 2 was decreased and those of renin form 5 and 6 were increased. These results suggest that the heterogeneity of renin release from cortical area of euhydrated and dehydrated rats in response to TMB-8 may be related to the changes of renal blood flow and/or calcium metabolism in cortical area. These data also suggest that the renin forms with different isoelectric points may have an physiological significance.

• 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.

• Korean Journal of Oriental Medicine
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• v.12 no.3 s.18
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• pp.59-67
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• 2006

Aims: Acupuncture has been used for the treatment of essential hypertension, but the efficacy and the mechanism of acupuncture in prevention of hypertension are still unclear. We tested the hypothesis that electroacupuncture (EA) applied to Baekhoe (GV20) changes NO/NOS system during development of hypertension in spontaneously hypertensive rats (SHR), and thereby causes the delay of development of hypertension in SHR. Methods: The male SHR rats in the developmental stages of hypertension (7-8 weeks) were randomly divided into three groups (control group, GV20 acupuncture group, and tail acupuncture group). And the age matched Wistar Koyto Rats (WKY) were randomly divided into two groups (nagative control, GV20 acupuncture group). EA treatments (10Hz, 1mA, 0.1ms) were carried out for 25 min/day for five consecutive days. The systolic blood pressure (SBP) was determined in conscious rats by the tail-cuff method using automatic BP mornitoring system. We investigated the activations of inducible NO synthase (iNOS) in nuclei of solitary tract (NTS) and rostral ventrolateral medulla (RVLM) of SHR by the western blotting method. Results: The SBP after the termination of EA stimulation applied to the GV20 was stabilized at $169.14{\pm}3.67$ mmHg which is lower value than that of the control group. The SBP of control group was elevated to $178.14{\pm}3.49$ mmHg. In addition, we evaluated NOS activity as well as iNOS protein expression of NTS and RVLM in both of SHR and WKY. The iNOS activity in NTS was significantly higher in SHR than in WKY. Furthermore, the iNOS activity of NTS showed significant decreases in EA groups compare to that of non treated SHR group. Although iNOS expression of RVLM showed non significant changes between SHR and WKY, EA significantly enhanced the iNOS expression in SHR. Our data support the hypothesis that delayed development of hypertension and altered iNOS expression of NTS and RVLM by EA stimulations in SHR rats. Conclusions: The findings demonstrate that acupuncture can change NO/NOS system in NTS and RVLM, and exert beneficial role on development of hypertension.

• The Journal of Internal Korean Medicine
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• v.32 no.3
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• pp.345-360
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• 2011

Objectives : This study was examined to investigate the effects of Cheonmagudeng-um gagam (CGG) extract on spontaneous hypertension. Methods : For the study of CGG, we divided rats into three groups. The normal group was Wister Kyoto rats (WKY). The control group was spontaneously hypertensive rats (SHR). The treatment group was SHR which were administered CGG extract (SHR-CGG). SHR-CGG were orally administered CGG extract that was diluted in distilled water at the various concentrations for 4 weeks (234.5 mg/kg) and SHR were orally administered the same dosage of plain distilled water as SHR-CGG. Then we measured anti-oxygen effects, ACE inhibitory activity, weight of heart and kidney, blood pressure, heart rate, plasma aldosterone, electrolyte, creatinine, uric acid, BUN, and observed the cortex of the cardiac muscle, kidney, and adrenal gland. Results : CGG increased DPPH scavenging activity and SOD similar activity depending on the concentration. CGG significantly decreased ROS, TNF-${\alpha}$, IL-6, IL-$1{\beta}$, heart weight, blood pressure, heart rate, aldosterone, and BUN in SHR. CGG increased ACE inhibition activity depending on the concentration. CGG inhibited the heart, kidney and adrenal gland tissue injury that is caused by hypertension. Conclusions : These results suggest that CGG is effective in treatment and prevention of hypertension.