• The Korean Journal of Physiology
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• 제22권1호
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• pp.41-53
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• 1988

The present study was undertaken to clarify the involvement of atrial natriuretic peptide in the development of hypertension in spontaneously hypertensive rats. Plasma concentration of immunoreactive atrial natriuretic peptide was higher in spontaneously hypertensive rats than in normotensive Sprague-Dawley and Wistar rats. Plasma renin concentration was lower in SHR than in normotensive rats, as observed in earlier experiments. Hydration-induced increase in urine flow and urinary excretions of sodium and potassium were smaller in SHR than in normotensive control rats. Intraarterial infusion of atrial natriuretic peptide resulted in increases in urine flow, urinary excretions of sodium and potassium in both hypertensive and normotensive rats. Renal response to atrial natriuretic peptide was markedly suppressed in SHR. Plasma renin and aldosterone concentration were suppressed by atrial natriuretic peptide in both SHR and normotensive rats. The responses were not significantly different in both groups. These results suggest that the renal responsiveness to atrial natriuretic peptide may be suppressed in SHR by some mechanisms still remaining obscure.

• The Korean Journal of Physiology
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• 제21권1호
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• pp.13-22
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• 1987

Effects of synthetic atrial natriuretic peptide and furosemide on the cardiovascular and renal functions were examined in the freshwater turtle, Amyda japonica. Both atria and ventricle of turtle contained an immunoreactive atrial natriuretic peptide. Synthetic rat atrial natriuretic peptide (atriopeptin III) and turtle atrial extract caused a decrease in mean arterial blood pressure and the vasodepressor effect was dose-dependent. In hydrated turtles received either atriopeptin III or turtle atrial extract, no significant change in renal function was observed until 100 min except a slight natriuresis at 60 or 100 min after injection of 30 ug/kg atriopeptin III or atrial extract, respectively. However, furosemide, 2 mg/kg, caused marked diuresis, natriuresis and kaliuresis. In non-hydrated turtles, no significant change in renal function was observed until 6 hrs following injection of 30 ug/kg atriopeptin III. Plasma aldosterone decreased at 2 hr and increased at 24 hr after injection of atriopeptin III although plasma renin concentration did not change. But, furosemide caused persistent diuresis, natriuresis and kaliuresis. Additionally, plasma aldosterone and renin concentrations were significantly increased at 24 hrs after injection of furosemide. In conclusion, we suggest that the freshwater turtle may have an atrial natriuretic peptide in heart and vascular receptors for atrial natriuretic peptide, and that atrial natriuretic peptide is more important in the regulation of blood pressure rather than that of renal function in freshwater turtles. We also suggest that an increased plasma renin concentration caused by furosemide may not be due to the sodium concentration delivered to macula densa, but due to the dehydration caused by persistent diuresis and natriuresis.

• The Korean Journal of Physiology
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• 제24권1호
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• pp.115-121
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• 1990

Pentobarbital 마취한 정상혈압 및 신성 고혈압 흰쥐에서 calcium channel 봉쇄 약물 nifedipine과 atrial natriuretic peptide(ANP)의 상호작용을 조사하였다. 정상혈압 흰쥐에서 nifedipine$(1.0\;{\mu}g/kg/min)$ 또는 ANP(60 ng/kg/min)의 주입은 각각 유의하게 혈압을 내렸으며 두 약물의 동시 주입시에 개별적으로 주입하였을 때보다 그 혈압내림의 정도가 더욱 컸다. Nifedipine은 단독 주입하였을 때에 신기능에 유의한 영향을 미치지 않았으나 ANP와 동시에 주입하였을 때에는 ANP의 요량 및 Na 배설 증가 효과를 항진시켰다. 한편 고혈압 흰쥐에서도 ANP의 혈압내림효과와 신장효과는 nifedipine과 함께 주입하였을 때에 더 컸다. 적출 흉부대동맥 표본을 phenylephrine으로 미리 수축시킨 후 ANP를 첨가하면 용량의존 이완반응을 보였고 nifedipine 존재하에서 더 예민하였다. 이상의 실험결과는 calcium channel 봉쇄약물이 ANP의 혈압내림효과를 항진시킴을 보인 것이며 그 기전으로 요중 배설 증가 및 혈관이완효과 증가 등이 관여함을 시사하였다.

• 대한한의학회지
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• 제18권2호
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• pp.267-272
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• 1997

The aim of the present experiments was to investigate the effect of Yukmijihwangtang water extracts on the plasma renin activity and plasma levels of atrial natriuretic peptide and aldosterone in rats. The results of this study were as follows: 1. Plasma renin activity decreased significantly after the administration of Yukmijihwangtang water extracts 1.5ml/kg. 2. Plasma levels of atrial natriuretic peptide (ANP) decreased significantly after the administration of Yukmijihwangtang water extracts. 3. Plasma levels of aldosterone increased significantly after the administration of Yukmijihwangtang water extract.

• 대한한의학회지
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• 제18권1호
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• pp.449-455
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• 1997

The aim of the present experiments was to investigate the effect of Yukmijihwangtang water extracts on the plasma renin activity and plasma levels of atrial natriuretic peptide and aldosterone in rats. The results of this study were as follows: 1. Plasma renin activity decreased significantly after the administration of Yukmijihwangtang water extracts 1.5 ml/kg. 2. Plasma levels of atrial natriuretic peptide (ANP) decreased significantly after the administration of Yukmijihwangtang water extracts. 3. Plasma levels of aldosterone increased significantly after the administration of Yukmijihwangtang water extract.

• The Korean Journal of Physiology and Pharmacology
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• 제4권3호
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• pp.235-241
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• 2000

We examined the expression of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) mRNAs upon isoproterenol (Iso)-induced cardiac hypertrophy in rats. Then, we tried to investigate the effects of sympatholytics to see if they can modulate the expression of ANP and BNP. In this study, RT-PCR technique was used to characterize the expression of ANP and BNP in right atrium (RA) and left ventricle (LV) of the hypertrophied rat heart. Histologic findings indicated that stimulation of ${\beta}-adrenoceptors$ with Iso for 5 days was sufficient to induce cardiac hypertrophy in rats. A continuous stimulation with Iso for 7 days resulted in an increase of the ANP and BNP expression in the LV and BNP expression in the RA. The increased expressions of ANP and BNP in the LV were slightly inhibited, and the increased expressions of BNP in the RA were markedly inhibited by a continuous treatment with propranolol, metoprolol, and clonidine for 7 days. Overall, our data present a differential expression of the natriuretic peptides in Iso-induced cardiac hypertrophy, and that the mechanisms involved in this differential ANP and BNP gene expression could be mediated via sympathetic nervous system.

• The Korean Journal of Physiology
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• 제20권1호
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• pp.103-124
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• 1986

Since it has been suggested that atrial receptor may be involved in the mechanism of extracellular volume regulation, it was shown that the granularity of atrial cardiocytes can be changed by water and salt depletion, and that an extract of cardiac atrial tissue, when injected intravenously into anesthetized rats, was shown to cause a large and rapid increase in renal excretion of sodium. Various natriuretic peptides were isolated and synthetized, and the effects were investigated by many workers. Most studies, however, have been carried out under anesthesia and there have teen some controversies over direct effect of the factor on the renal function. Therefore, it was attempted in this study to access the effects of an atrial extract and a synthetic natriuretic factor in unanesthetized rabbits. Intrarenal arterial infusion of atrial extract caused a rapid increase of urinary volume and excretion of sodium. Glomerular filtration rate and renal plasma flow were both increased with no change in filtration fraction. The ventricular extract produced no change in urinary excretion of electrolytes, nor in renal hemodynamics. Intrarenal infusion of synthetic atrial natriuretic factor caused increases of renal excretory rate of sodium, chloride and potassium, and $FE_{Na}$. Glomerular filtration rate, renal plasma flow increased. And free water clearance also increased. Accentuated excretory function correlated well with increased glomerular filtration rate and renal plasma flow during infusion and for 10 minutes following the cessation of the infusion. Renin secretion rate decreased during constant infusion of atrial natriuretic factor. However, no correlation was found with the changes in glomerular filtration rate, renal plasma flow, or urinary excretion of sodium. These results suggest that atrial extract or atrial natriuretic factor induces changes in renal hemodynamics, as in excretion of electrolytes either indirectly through hemodynamic changes or directly by inhibiting tubular reabsorption. At the same time, renin secretory function is affected by the factor possibly through an unknown mechanism.

• 대한소아치과학회지
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• 제28권1호
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• pp.72-81
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• 2001

Dendroaspis natriuretic peptide (DNP)는 최근에 green Mamba snake Dendroaspis angusticeps의 독(venom)에서 발견된 17개의 아미노산 disulfide링 구조를 포함하는 38개 아미노산 펩티드로 natriuretic peptide family와 그 구조가 비슷하다. Natriuretic peptide family는 사람과 흰쥐 비만세포로부터 히스타민을 유리시킨다고 알려져 있다. 그러나 DNP가 비만 세포로부터 히스타민을 유리 시키는 여부는 밝혀져 있지 않다. 본 연구는 DNP가 흰쥐 복강 비만세포로부터 히스타민을 유리시키는 여부와 함께 히스타민 유리기전을 구명하고자 실시되었다. 다양한 농도의 DNP를 흰쥐 복강 비만세포에 처리한 다음, 비만세포의 탈과립을 도립 광학현미경으로 관찰하였다. 히스타민 유리량은 방사효소법으로 측정하였고 세포내 칼슘 유입량과 cyclic GMP의 수준은 방사면역법으로 측정하였다. DNP는 흰쥐 복강 비만세포를 탈과립시켰고 농도가 증가함에 따라 비만세포로부터 히스타민 유리량이 증가되었다. 또한 DNP는 농도 증가에 비례하여 비만세포 안으로 세포밖의 칼슘을 유입시켰으며 세포안의 cyclic GMP의 수준을 증가시켰다. 이상의 결과로 미루어, DNP는 비만세포 안의 cyclic GMP와 칼슘의 농도를 증가시켜 비만세포로부터 히스타민을 유리시키는 것으로 생각된다.

• 대한소아치과학회지
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• 제28권3호
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• pp.447-463
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• 2001

Dendroaspis natriuretic peptide(DNP)는 Dendroaspis angusticeps의 뱀독으로부터 추출된 natriuretic peptide의 새로운 일원으로서, 사람의 혈장과 심방 근육에 존재하고 실험동물에서 혈관확장과 이뇨작용을 나타내는 것으로 알려져있다. 그러나 아직까지 심장 이외의 다른 기관내에 DNP가 존재하는지 또한 이들이 현재까지 알려진 기능 이 외의 또다른 생리적 기능을 나타내는 지의 여부는 아직 확실하게 밝혀져 있지 않다. 타액전 내에서 DNP의 기능을 규명하기 위한 전단계로, 먼저 흰쥐의 타액선내에 DNP가 존재하는지를 면역조직화학법을 이용하여 알아보았고 또한 DNP의 수용체가 타액전 또는 구강점막내에 존재하는 지의 여부를 생체외 방사선자기법을 이용하여 알아보았다. DNP의 면역반응은 악하선과 설하선 및 이하선에서 주로 도관부위에서 관찰되었고, 선포부위에서는 관찰되지 않았다. atrial natriuretic peptide(ANP)의 면역반응 역시 악하선과 설하선 및 이하선에서 DNP 면역반응과 유사하게 주로 도관부위에서 관찰되었다. DNP에 특이한 수용체가 타액선에는 저밀도로 존재한 반면 경구개와 혀 점막상피부위에서는 고밀도로 존재하였다. 경구개와 혀 점막상피부위의 DNP수용체는 주로 상피의 기저층과 기저층에 인접한 유극세포층에 국한되어 존재하는 것을 미세방사선자기법을 통하여 알 수 있었다. 이러한 결과로 볼 때 DNP가 타액선과 구강점막 부위에서 어떠한 생리적 기능을 나타낼 것으로 여겨지는데, 특히 구강점막 부위에서는 점막상피세포의 성장과 성숙과정에 관여하리라 추정된다.

• The Korean Journal of Physiology
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• 제24권1호
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• pp.131-144
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• 1990

It is well known that the atrial natriuretic peptide (ANP) has a prepro-hormone of 151 amino-acids which loses their hydrophobic signal peptide to form 126 amino acid prohormone. The whole prohormone is released and then cleaved by proteases into more than one circulating forms. Recently, Winters et al. (1988a, b) reported that high concentrations of N-terminal fragments of prepro-ANP $(26{\sim}55),\;(56{\sim}92)\;and\;(104{\sim}123)$ were detected in human plasma. However, their physiological roles have not been established. The present study was conducted to determine whether the N-terminal fragments of pro-ANP have any effect on the renal function and to compare the effect with those of G-terminal fragments of pro-ANP The results indicate that intrarenal arterial infusions of prepro-ANP $(26{\sim}41),\;(26{\sim}55),\;(56{\sim}92)\;and\;(104{\sim}123)$ induced no significant changes in renal function. Whereas ${\alpha}-human$ ANP $(prepro-ANP,\;124{\sim}151)$ and pro-ANP caused a significant increase in urine volume, renal plasma flow, glomerular filtration rate, urinary excretions of sodium, chloride and potassium, and fractional excretion of sodium. These results suggest that the N-terminal fragments of pro-ANP are ineffective, while the C-terminal fragments retain the natriuretic and diuretic activities.