• The Korean Journal of Physiology and Pharmacology
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• v.6 no.2
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• pp.127-130
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• 2002

The present study was aimed to investigate whether the adriamycin-induced nephrosis is associated with an altered regulation of local renin-angiotensin system (RAS) in the kidney. Rats were subjected to a single injection of adriamycin (2 mg/kg body weight, IV) and kept for 6 weeks to allow the development of nephrosis. They were then divided into two groups, and supplied with and without cilazapril, an angiotensin converting enzyme (ACE) inhibitor, in drinking water (100 mg/l) for additional 6 weeks. Another group without adriamycin-treatment served as control. The mRNA expression of renin, ACE, type 1 and type 2 angiotensin II receptors (AT1R, AT2R), and transforming growth factor $(TGF)-{\beta}1$ was determined in the cortex of the kidney by reverse transcription-polymerase chain reaction. Adriamycin treatment resulted in heavy proteinuria. Accordingly, the mRNA expression of renin, ACE, and AT1R was increased in the renal cortex, while that of AT2R was decreased. Co-treatment with cilazapril attenuated the degree of proteinuria. While not affecting the altered expression of renin, cilazapril decreased the expression of ACE to the control level. Cilazapril further increased the expression of AT1R, while it restored the decreased expression of AT2R. The expression of $(TGF)-{\beta}1$ was increased by the treatment with adriamycin, which was abolished by cilazapril. An altered expression of local RAS components may be causally related with the development of adriamycin-induced nephrosis, in which AT1R is for and AT2R is against the development of nephrosis.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.3
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• pp.315-320
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• 1999

Molecular regulation of the renin-angiotensin system (RAS) was investigated in deoxycorticosterone acetate (DOCA)-salt hypertension. The expression of renin, angiotensinogen and angiotensin II receptor genes in the kidney and liver was determined by Northern blot analysis in rats which were made DOCA-salt hypertensive over the period of 2 or 4 weeks. Along with the hypertension, renin mRNA was decreased in the remnant kidney. The expression of angiotensinogen gene was not significantly altered in the kidney, but was significantly decreased in the liver. The expression of angiotensin II receptor gene was increased in the kidney, while it remained unaltered in the liver. The duration of hypertension did not affect the altered gene expression. It is suggested that the components of RAS are transcriptionally regulated in DOCA-salt hypertension in a tissue-specific manner.

• The Korean Journal of Physiology
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• v.30 no.1
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• pp.33-41
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• 1996

The present study was aimed to investigate the role of endothelium-derived nitric oxide (NO) in the control of renin release and to examine if NO is implicated in the development of two-kidney, one clip (2K1C) hypertension. Male Sprague-Dawley rats $(150{\sim}200\; g)$ were constricted at the left renal artery. They were then supplemented with $N^{G}-nitro-L-arginine\;methyl\;ester\;(L-NAME,\; 5mg/100\;mL)$ or with L-arginine hydrochloride (400 mg/100 mL) in the drinking water. The control group was supplied with normal tap water. The sham-clipped rats were operated as in 2K1C rats except for that no clip was made. The kidneys were taken to examine in vitro release of renin at days 7 and 14 following clipping the renal artery. Northern blot analysis was also done to assess the expression of renin gene in the kidney. In sham-clipped rats, L-NAME caused a sustained increase of the blood pressure, whereas L-arginine was without effect. Neither L-NAME nor L-arginine-supplementation significantly affected the development of hypertension in 2K1C rats. Plasma renin concentration (PRC) measured on day 28 did not significantly differ among the L-NAME, L-arginine and control groups either in 2K1C or in sham-clipped rats. Renin contents (RRC) in the clipped kidney were increased, while those in the contralateral kidney were decreased. The release of renin in vitro from cortical slices was also enhanced in the clipped kidney, whereas it was attenuated in the contralateral. Comparing the RRC and in vitro release, the latter was more rapidly decreased than the former in the contralateral kidney. The renin mRNA levels in the contralateral kidney were almost at their nadir at days 7 and 14 in 2K1C rats. It is suggested that NO does not affect the development of 2K1C hypertension in which the renin-angiotensin system has been activated. The data also confirm that RRC and renin gene expression are increased in the clipped kidney and suppressed in the contralateral kidney in 2K1C rats.

• Nutrition Research and Practice
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• v.17 no.2
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• pp.192-205
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• 2023

BACKGROUND/OBJECTIVES: It is known that the renin-angiotensin system (RAS) in the brain could regulate cognitive functions as well as blood pressure. Inhibition of RAS for the improvement of cognitive function may be a new strategy, but studies so far have mostly reported on the effects of RAS inhibition by drugs, and there is no research on cognitive improvement through RAS inhibition of food ingredients. Therefore, this study investigated the effect of curcumin on blood pressure and cognitive function and its related mechanism in spontaneously hypertensive rat/Izm (SHR/Izm). MATERIALS/METHODS: Six-week-old SHR/Izm rats were divided into 5 groups: control group (CON), scopolamine group (SCO, drug for inducing cognitive deficits), positive control (SCO and tacrine [TAC]), curcumin 100 group (CUR100, SCO + Cur 100 mg/kg), and curcumin 200 group (CUR200, SCO + Cur 200 mg/kg). Changes in blood pressure, RAS, cholinergic system, and cognitive function were compared before and after cognitive impairment. RESULTS: The SCO group showed increased blood pressure and significantly reduced cognitive function based on the y-maze and passive avoidance test. Curcumin treatments significantly improved blood pressure and cognitive function compared with the SCO group. In both the CUR100 and CUR200 groups, the mRNA expressions of angiotensin-converting enzyme (ACE) and angiotensin II receptor type1 (AT1), as well as the concentrations of angiotensin II (Ang II) in brain tissue were significantly decreased. The mRNA expression of the muscarinic acetylcholine receptors (mAChRs) and acetylcholine (ACh) content was significantly increased, compared with the SCO group. CONCLUSIONS: The administration of curcumin improved blood pressure and cognitive function in SCO-induced hypertensive mice, indicating that the cholinergic system was improved by suppressing RAS and AT1 receptor expression and increasing the mAChR expression.

• Nutrition Research and Practice
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• v.11 no.5
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• pp.388-395
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• 2017

BACKGROUND/OBJECTIVES: Although Korean fermented foods contain large amounts of salt, which is known to exacerbate health problems, these foods still have beneficial effects such as anti-hypertension, anti-cancer, and anti-colitis properties. We hypothesized that ganjang may have different effects on blood pressure compared to same concentrations of salt. MATERIALS/METHODS: Sprague-Dawley rats were divided into control (CT), NaCl (NC), and ganjang (GJ) groups and orally administered with 8% NaCl concentration for 9 weeks. The systolic blood pressure (SBP), serum chemistry, $Na^+$ and $K^+$ concentrations and renal gene expressions were measured. RESULTS: The SBP was significantly increased in the NC group compared to the GJ and CT groups. In addition, the $Na^+$ concentration in urine was higher in the GJ and NC groups than the CT group, but the urine volume was increased in the GJ group compared to the other groups. The serum renin levels were decreased in the GJ group compared to the CT group, while the serum aldosterone level was decreased in the GJ group relative to the NC group. The mRNA expression of the renin, angiotensin II type I receptor, and mineralocorticoid receptor were significantly lower in the GJ group compared to other groups. Furthermore, GJ group showed the lowest levels of genes for $Na^+$ transporter in kidney cortex such as $Na^+/K^+$ $ATPase{\alpha}1$ ($NKA{\alpha}1$), $Na^+/H^+$ exchanger 3 (NHE3), $Na^+/HCO_3{^-}$ co-exchanger (NBC), and carbonic anhydrases II (CAII). CONCLUSIONS: The decreased SBP in the GJ could be due to decreased renin and aldosterone levels in serum and increased urinary volume and excretion of $Na^+$ with its transporter gene alteration. Therefore, ganjang may have antihypertensive effect despite its high contents of salt.

• Nutrition Research and Practice
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• v.15 no.2
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• pp.160-172
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• 2021

BACKGROUND/OBJECTIVES: Nutritional status and food intake during pregnancy and lactation can affect fetal programming. In the current metabolic syndrome epidemic, high-fructose diets have been strongly implicated. This study investigated the effect of maternal high-fructose intake during pregnancy and lactation on the development of metabolic syndrome in adult offspring. SUBJECTS/METHODS: Drinking water with or without 20% fructose was administered to female C57BL/6J mice over the course of their pregnancy and lactation periods. After weaning, pups ate regular chow. Accu-Chek Performa was used to measure glucose levels, and a tail-cuff method was used to examine systolic blood pressure. Animals were sacrificed at 7 months, their livers were excised, and sections were stained with Oil Red O and hematoxylin and eosin (H&E) staining. Kidneys were collected for gene expression analysis using quantitative real-time Polymerase chain reaction. RESULTS: Adult offspring exposed to maternal high-fructose intake during pregnancy and lactation presented with heavier body weights, fattier livers, and broader areas under the curve in glucose tolerance test values than control offspring. Serum levels of alanine aminotransferase, aspartate aminotransferase, glucose, triglycerides, and total cholesterol and systolic blood pressure in the maternal high-fructose group were higher than that in controls. However, there were no significant differences in mRNA expressions of renin-angiotensin-aldosterone system genes and sodium transporter genes. CONCLUSIONS: These results suggest that maternal high-fructose intake during pregnancy and lactation induces metabolic syndrome with hyperglycemia, hypertension, and dyslipidemia in adult offspring.

• Applied Microscopy
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• v.39 no.2
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• pp.81-87
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• 2009

Diabetic retinopathy is one of major complications of diabetes mellitus, which is associated with the dysfunction of retina. It has been reported that the onset of diabetic retinopathy is related to the activation of renin-angiotensin system (RAS). Angiotensin converting enzyme (ACE), which converts angiotensin I into angiotensin II, is a key component of RAS. Among many growth factors, vascualr endothelial growth factor (VEGF) is an important cytokine in the neovasculization of retina, which is a characteristics of diabetic retinopathy. However, the relationship between ACE and VEGF was not elucidated in diabetic retinopathy. Thus, this study was conducted to examine the protective effect of captopril, an ACE inhibitor, in the retina of streptozotocin (STZ)-treated diabetic rats. In present study, STZ-treated diabetic rats exhibited the increase of VEGF levels in serum and retina. The serum levels of VEGF in STZ-treated diabetic rats was not blocked by the treatment of captopril. However, the retina levels of VEGF in STZ-treated diabetic rats was blocked by the treatment of captopril, suggesting the local action of captopril in retina. Immunohistochemical analysis also revealed that the retina of STZ-treated diabetic rats manifested the increase of ganglion cell layers, outer nuclear layers, and inner nuclear layers, which were also prevented by the treatment of captopril. In conclusion, captopril prevented the expression of VEGF in the retina of STZ-treated diabetic rats.