• The Korean Journal of Physiology
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• v.23 no.1
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• pp.51-66
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• 1989

Mammalian cardiocytes secrete atrial natriuretic peptides (ANPs) into plasma, which cause marked natriuresis, diuresis, vasorelaxation and inhibition of hormone secretions. Aging influences the ability of the kidney both to conserve and to excrete sodium; i.e., in old animals, the excretory capacity of sodium is reduced and the time required to excrete sodium load is prolonged. Therefore, it is possible that animals differing in ages may respond differently to ANP. In the present study, we determined whether the renal, hormonal and vascular effects of ANP may be influenced by aging in conscious rabbits. The plasma renin concentration decreased with aging but plasma ANP concentration was significantly lower only in 24-month-old rabbits. Plasma aldosterone concentration and atrial ANP content did not change by aging. In 1-month-old rabbits, ANP (atriopeptin III, 3 ug/kg) administered intravenously caused hypotension and decreased in plasma renin and aldosterone concentrations, but did not cause diuresis and natriuresis. In 2 to 5 month-old rabbits, ANP caused hypotension, decreases in Plasma renin and aldosterone concentrations and marked renal effects. However, in 24-month-old rabbits, all the above effects of ANP was blunted. With hydration of physiological saline at a rate of 15 ml/kg/h for 2hr, urine volume and glomerular filtration rate did not change but the electrolyte excretion as well as fractional excretion of sodium significantly increased. The plasma concentrations of active renin and aldosterone were decreased but plasma inactive renin and ANP concentrations were increased. The changes in renal function and plasma level of hormone showed no differences in different ages. These results suggest that the peripheral vascular receptors to ANP may develop earlier than those in the kidney, and the attenuated vascular and renal responses to ANP in the old age may be due to age-related modifications in renal function and blood vessel.

• The Korea Journal of Herbology
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• v.21 no.2
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• pp.143-150
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• 2006

Oriental pear was used as treatment of asthma, control of blood pressure tonic medicine diabetes in oriental medicine, Pear Pectin was effective on control of blood pressure in previous report. In this study, it was investigated that Woohwang with pear extractions effects on cardiovascular system as blood pressure and renin and Atrial natriuretic peptide(ANP) in plasma. The 2K1C hypertension model was prepared by constricting the left renal artery with a sliver dip. Animals were then divided into three groups, control, Woowhang:Pear Phenolic compound(1:1), Woowhang:Pear Phenolic compound(2:1),Woowhang:Pear Phenolic compound(1:2) were supplied with them. Direct-blood pressure was measured at femoral vein, Indirect-blood pressure was measured at rodent tail. The results are as follows. The blood pressure was more significantly decreased at 1:2(woohwang:pear phenolic compound)group than other groups. On 6,9,12,15days, the blood pressure was significantly decreased in 1:2(woohwang:pear phenolic compound)group. The plasma ANP was significantly increased in 1:2(woohwang:pear phenolic compound)group. It tenders to decrease in 1:2(woohwang:pear phenolic compound)group on plasma renin. Based on the above results it is assumed that oral administration of Woohwang with Pear Phenolic compound(1:2) can help the treatment of hypertension.

• The Korean Journal of Physiology
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• v.23 no.2
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• pp.253-261
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• 1989

Responses of atrial natriuretic peptide (ANP), aldosterone and renin release to acute volume expansion were compared in normotensive Wistar and spontaneously hypertensive rat (SHR) fed low or high-sodium diet (2 or 25 mmol Na/100 g diet). Experimental diets were fed for 6 weeks from 7-week-old and the growth rate was similar in all groups. In the morning of the experiment, catheters were inserted under ether anesthesia in femoral artery for pressure recording and blood collection, femoral vein for saline infusion, and bladder for urine collection. Then, the rats were placed in restraining cages. When the rats were recovered from anesthesia and the arterial pressure became stabilized, control urine and blood samples were collected. Then, 0.9% saline was infused for 30 min for volume expansion (3% BW). Arterial pressure was significantly higher in the high-sodium SHR but there was no difference between the two groups of Wistar rats. Control plasma levels of Na, K, ANP, renin activity, and hematocrit were not different among the 4 groups. However, plasma aldosterone level was significantly higher in the low-sodium groups. Wistar low-sodium rats showed approximately two times higher plasma aldosterone level than the SHR counterpart. Volume expansion produced a marked increase in plasma ANP level, especially in the high-sodium groups. The low-sodium groups of both strains showed approximately two-fold increase in plasma ANP level. Following a volume expansion plasma aldosterone level and renin activity decreased in all groups. There was a significant logarithmic positive correlation between plasma renin activity and aldosterone concentration. The low-sodium rats produced a greater increase in aldosterone release by small increase in plasma renin than did the high-sodium rats. The low- and high-sodium rats produced a similar degree of diuresis and natriuresis after volume expansion. However, SHR produced a greater natriuresis than did the Wistar rats. The above results indicate that regulatory mechanisms of ANP, aldosterone and renin release are different between the normotensive and hypertensive rats, and between the low- and high-sodium groups.

• The Korean Journal of Physiology
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• v.24 no.2
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• pp.319-329
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• 1990

Effects of atrial natriuretic peptide (ANP) on blood pressure, plasma lenin activity, aldosterone and renal excretion were compared in conscious spontaneously hypertensive rats (SHR) and normotensive Wistar rats fed low, medium or high sodium diet (2, 10, 25 mmol NaCl/100g diet) for 6 weeks. ANP infusion (380 ng/kg/min for 20 min) produced reductions in blood pressure, plasma renin activity, and aldosterone level, but marked increases in hematocrit, urine flow, and excretions of sodium and potassium. The low sodium group showed a significantly enhanced aldosterone lowering effect of ANP than the high sodium group. However, three salt groups showed no difference in effects of ANP on blood pressure, plasma renin activity, hematocrit and diuresis. Natriuretic response to ANP was significantly greater in the high salt-than in the low sait-SHR, but was not different between the Wistar salt groups. There were strain differences in effects of ANP: SHR showed greater responses of blood pressure and natriuresis than Wistar rats. Above results indicate that aldosterone-lowering and natriuretic effects of ANP were modifed by different dietary sodium intakes. However, blood pressure- and renin-lowering, or diuretic effects of ANP were not affected by dietary sodium intakes. The mechanisms whereby dietary sodium intakes alter the effects of ANP in the pathogenesis of hypertension are not clear.

• The Korean Journal of Physiology
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• v.23 no.1
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• pp.43-49
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• 1989

Effects of atrial natriuretic peptide (ANP) on the development of hypertension in 2-kidney, 1-clip (2-K, 1-C) rats were examined. In one group of rats, ANP infusion (500 ng/hr, iv) started immediately after clipping the renal artery. Another group of rats with one kidney-clipped was without ANP infusion and served as a control. Blood pressure was measured on days 4, 7, and 10 following clipping the renal artery. Upon the last blood pressure measurement finished, blood sample was collected by decapitation to measure plasma renin activity (PRA), and both kidneys were taken to weigh and to measure renin content. The ANP-infused group showed an attenuation of increases in blood pressure compared to the non-infused control group. PRA was lower in the ANP-infused group than in the non-infused group. Cortical renal renin content (RRC) of the clipped kidneys was not different between ANP-infused and non-infused groups. The clipped kidneys showed a higher RRC and weighed less than the non-clipped contralateral kidneys within each group. In contrast, sham-clipped rats did not show significant changes in any of the parameters examined regardless of whether ANP was infused or not. These results demonstrate that chronic ANP infusion does not prevent but does attenuate the development of hypertension in 2-K, 1-C rats. It is suggested that ANP plays a role in the long-term regulation of blood pressure, at least in part, by antagonizing the renin-angiotensin-system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.700-705
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• 2003

Oriental pear was used as treatment of asthma, control of blood pressure tonic medicine vasoactio, diabetes in oriental medicine. In this study, it was investigated that pear pectin effects on cardiovascular system as blood pressure and renin and atrial natriuretic peptide (ANP) in plasma, cardiac hypertrophy. The experiments were performed on Sprague-Dawley rats, 2K1C hypertension model was prepared by constricting the left renal artery with a sliver clip. Animals were then divided into four groups, 5 mg/kg, 10 mg/kg, 15 mg/kg and the control, pear pectin and apple pectin solutions were supplied with them. The blood pressure was more decreased in pear pectin 10 mg/kg than in apple pectin. The plasma ANP was decreased in pear pectin 10 mg/kg, and renin was increased in same concentration of drug. Cardiac hypertrophy had a tendency to decrease in pear pectin 15 mg/kg, but was not statistically significant compared to control group.

• Journal of Acupuncture Research
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• v.15 no.2
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• pp.349-356
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• 1998

The aim of the experiments was to investigate the effect of Semen Cuscutae aqua-acupuncture at the meridian point BL 20(脾兪) and BL 23(賢兪) on the blood pressure, plasma renin activity, plasma levels of aldosterone and atrial natriuretic peptide (ANP) in spontaneously hypertensive rats (SHR). The results of this study were as follows: 1. Systolic blood pressure was decreased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 20, BL 23. 2. Plasma renin activity was increased significantly after Semen Cuscutae aqua-acupuncture at meridian point BL 23, BL 20. 3. Plasma levels of aldosterone was increased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 20. 4. Plasma levels of atrial natriuretic peptide (ANP) was increased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 23, but it was decreased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 20. These results suggest that the changes of the depressor response after Semen Cuscutae aqua-acupuncture at the meridian point BL 20, BL 23 are related to the changes of the plasma renin activity, plasma levels of atrial natriuretic peptide (ANP) and aldosterone.

• The Korean Journal of Physiology
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• v.23 no.1
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• pp.67-78
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• 1989

Since the atrial receptor was suggested to be involved in the control of extracellular fluid volume, it has been shown that the granularity of atrial cardiocytes can be changed by water and salt depletion, and that an extract of atrial tissue, when injected intravenously into anesthetized rats, causes a large and rapid increase in renal excretions of sodium and water. The immunoreactive atrial natriuretic peptide (ANP) has been found in the plasma of patients suffering from various cardiovascular diseases. A high level of ANP in the plasma has been reported in essential hypertension. Several studies on the effects of ANP on renal function and arterial blood pressure have presented contradictory results showing attenuated or accentuated responses. Thus, involvement of the ANP in the development of hypertension remains unresolved. Present study was undertaken to investigate whether the ANP is involved in the development of hypertension in two-kidney one-clip Goldblatt hypertensive rats. The plasma concentration of immunoreactive ANP appeared to be significantly elevated in hypertensive rats as compared with normotensive Goldblatt operated and sham-operated rats. Plasma renin concentration was higher in hypertensive rats than in normotensive rats, as observed in earlier experiments. Intravenous infusions of ANP resulted in increases of urine flow and urinary excretions of sodium and potassium in both hypertensive and normotensive rats. The renal response to ANP was markedly accentuated in Goldblatt hypertensive rats. The plasma concentration of ANP showed a linear relationship with the arterial blood pressure. Infusions of ANP reduced blood pressure both in hypertensive and normotensive rats. These results suggest that in Goldblatt hypertensive rats an elevation of ANP level in the plasma may not be a cause, but instead a consequence of hypertension, and that the renal responsiveness to the ANP is accentuated by some unknown mechanisms.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.363-367
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• 2003

Oriental pear was used as treatment of asthma, control of blood pressure tonic medicine vasoaction, diabetes in oriental medicine. In this study, it was investigated that pear phenolic compound effects on cardiovascular system as blood pressure and renin and atrial natriuretic peptide(ANP) in plasma, Cardiac hypertrophy. The experiments were performed on Sprague Dawley rats, 2K1C hypertension model was prepared by constricting the left renal artery with a sliver clip. Animals were then divided into four groups, 5mg/Kg(PPC-A) 10mg/Kg(PPC-B) 15mg/Kg(PPC-c) and control group. Pear phenolic compound solution were supplied with them for 3weeks, a day's interval. The results are that The blood pressure was significantly decreased at 15days in PPC-A group than control group. The plasma ANP was increased in PPC-A and PPC-C group, and cardiac hypertrophy was significantly decrease in PPC-C group compared with control group.

• The Journal of Korean Medicine
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• v.20 no.2
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• pp.141-145
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• 1999

The aim of this experiment was to investigate the effects of a mixture of Scutellariae Radix, Coptidis Rhizoma and Coptidis Rhizoma water extracts on the blood pressure, plasma renin activity, plasma levels of aldosterone and atrial natriuretic peptide (ANP) in spontaneously hypertensive rats (SHR). The results of this study were as follows: 1. Systolic blood pressure decreased significantly after the administration of a mixture of Scutellariae Radix, Coptidis Rhizoma, and Coptidis Rhizoma water extract 0.2 ml/200g. 2. Plasma renin activity and plasma levels of ANP were not changed after the administration of a mixture of Scutellariae Radix, Coptidis Rhizoma and Coptidis Rhizoma water extracts, 3. Plasma levels of aldosterone was increased significantly after the administration of a mixture of Scutellariae Radix, Coptidis Rhizoma and Coptidis Rhizoma water extracts 0.1 ml/200g.