• The Korean Journal of Physiology
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• v.5 no.1
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• pp.59-69
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• 1971

Studies were undertaken on the changes in the renal blood flow by relating them with the alterations in the amplitudes in the rheogram of rabbits. The changing pattern of the electrical conductivity was recorded by means of the needle electrodes inserted into the kidney and the surrounding aluminium foil which was grounded. The Impedance Rheograph manufactured by the Narco Company was used. The small artifact which persisted after ligation of the renal vessels was subtracted from the value obtained in each pulsatile wave in the rheogram. The animals were nembutalized intravenously, 30 mg/kg. A plastic canule was inserted into the carotid artery and the arterial blood pressure was monitored continuously with the pressure transducer connected to the physiograph. Stepwise bleedings were performed on the animal. The first bleeding was between 13 to 18 ml in the amount, and it was folowed by consecutive hemorrhages, 5 or 10 ml each time. The total amount of bleeding was summed as much as 1.5-2% of the body weight. Two minutes fter each bleeding th arterial blood pressure, ECG and the rheogram were taken. That was the necessary time to obtain the stabilized picture of each parameter. After closing the bleeding process, the shed blood was retransfused into the animal and the response in the renal blood flow was observed as well as the arterial blood pressure. Particularly the presence or absence of the autoregulatory mechanism in the situation of the hemorrhage was also studied. The results obtained were as follows: 1. In 7 cases out of 22, that was about one third of the total number of experiments, the autoregulatory mechanism of the renal blood flow persisted even in acute hemorrhage, and the decreases in the renal blood flow were less than 10% of the control values even when the arterial blood pressure dropped to 66-87% of the original value obtained before the bleeding. 2. Because of the stepwise bleeding the exact blood pressure at which the renal blood flow reduced as much as one third of the control value could not be obtained. However, the results revealed that the approximate pressure, expressed as percentage of the control value, was 50-60% in 3 cases, 61-70% in 4 cases and 71-80% in 8 cases. In one case the decrease in the renal blood flow exceeded one third of the control value before the pressure dropped to 80% of the control. 3. In 19 cases the decreases in the renal blood flow exceeded one half of the control values by hemorrhage. Then the arterial blood pressure revealed less than 40% of the control value in 6-cases. In 2 cases the pressure was 51-60% of the control pressure. In 5 cases the range of bleed pressure was 61-70%, and in e remaining 6 cases the pressure ranged from 71 to 80% of e control value. 4. Out of 15 cases of retransfusion after definite decreases in the renal blood flow loller·ing the hemorrhage, 9 cases restored their renal blood flow. On the contrary 6 cases showed low values even when the shed blood was retransfused. 5. Theories concerning the mechanism of the autoregulation of the renal blood flow were reviewed for the purpose of explanation of the results obtained. However, there are much to be done before greater satisfaction

• Journal of Chest Surgery
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• v.17 no.1
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• pp.101-109
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• 1984

The influences of acute respiratory and metabolic acid-base disturbances on the carotid, renal and coronary blood flow were measured in dogs. Respiratory acidosis was induced by artificial respiration with 8% CO2 -02 gas mixture and respiratory alkalosis was induced by hyperventilation under the control of respirator. Metabolic acidosis and metabolic alkalosis were induced by intravenous infusion of 0.3N hydrochloric acid and 0.6M sodium bicarbonate solution. To observe the effect of hyperkalemia, isotonic potassium chloride solution was infused. CVI electromagnetic flowmeter probes were placed on the left common carotid artery, left renal artery and left circumflex coronary artery. Each flow was recorded on polygraph. 1. The carotid blood flow showed rapid showed rapid and marked increase in acute respiratory acidosis. Even in the cases when arterial blood pressure was lowered during the state of respiratory acidosis, carotid blood flow increased. By the infusion of hydrochloric acid, carotid blood flow increased slowly and returned to the previous label after discontinuation of the infusion. Carotid blood flow also increased by the infusion of large amount of sodium bicarbonate, but it might be the combined effect of expansion of extracellular fluid and compensatory elevation of carbon dioxide tension. 2.The renal blood flow remained unchanged during the acute acid-base disturbances, suggesting effective autoregulation. Renal blood flow, however, increased very slowly when the infusion of potassium chloride continued for a long period. 3.Although less marked than the carotid blood flow, the coronary blood flow increased in the acute respiratory and metabolic acidosis. In asphyxiated condition, coronary blood flow increased most markedly and this might be the combined effect of hypoxia, hypercapnea, and lowering of pH. In summary, the carotid blowflow showed more marked change in the acute respiratory and metabolic acidosis than the renal and coronary blood flow. Respiratory and metabolic components of acid-base disturbances may influence the local blood flow concomitantly, there being more differences in the individual responses, but respiratory component manifested more rapid and marked effect than metabolic component.

• YAKHAK HOEJI
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• v.28 no.3
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• pp.149-160
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• 1984

In order to certify the diuretic mechanism of dopamine, this study was performed in dog. The following results were obtained. Dopamine, when given intravenously, produced diuresis, and increased glomerular filtration rate (GFR), renal plasma flow (RPF), and amount of sodium excreted in urine. When infused directly into a renal artery, dopamine elicited a marked diuresis confined only to the infused side, with concomitant rises in osmolar clearance and sodium excretion as well as a slight increase in free water clearance. Simultaneously total renal plasma flow and medullary plasma flow increased markedly with a increase of glomerular filtration rate and renal plasma flow. Medullary concentration gradient of sodium also markedly lowered in the infused kidney. These changes were not observed during mannitol diuresis and renal action of dopamine were not apparent in dog pretreated with haloperidol. From the above experimental results, it is thought that dopamine, when given into a vien or infused directly into a renal artery, induces diuresis, and the mechanism of its action is due to dual actions which are hemodynamic effect along with glomerular filtraction rate, and the increased response in the medullary blood flow.

• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.449-454
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• 2007

An electrohydraulic (EH) pump-driven closed-loop blood pressure regulatory system was developed based on flow-mediated vascular occlusion using the vascular occlusive cuff technique. It is very useful for investigating blood pressure-dependant physiological variability, in particular, that could identify the principal mediators of renal autoregulation, such as tubuloglomerular feedback (TGF) and myogenic (MYO), during blood pressure regulation. To address this issue, renal perfusion pressure (RPP) should be well regulated under various experimental conditions. In this paper, we designed a new EH pump-driven RPP regulatory system capable of implementing precise and rapid RPP regulation. A closed-loop servo-controlwas developed with an optimal proportional plus integral (PI) compensation using the dynamic feedback RPP signal from animals. An in vivo performance was evaluated in terms of flow-mediated RPP occlusion, maintenance, and release responses. Step change to 80 mmHg reference from normal RPP revealed steady state error of ${\pm}3%$ during the RPP regulatory period after PI action. We obtained rapid RPP release time of approximately 300 ms. It is concluded that the proposed EH RPP regulatory system could be utilized in in vivo performance to study various pressure-flow relationships in diverse fields of physiology, and in particular, in renal autoregulation mechanisms.

• The Korean Journal of Pharmacology
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• v.5 no.2
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• pp.141-148
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• 1969

The direct effect of isoproterenol on renal function, when given intravenously, is usually obscured by its potent hypotensive action. To obviate the latter action, isoproterenol was infused directly into one renal artery of the dog, the other kidney serving as a control for the general action. And following results were obtained. In the first series of experiments, the directic action of isoproterenol was ascertained. $1.0\;{\mu}g/kg/min$. reduced on both kidneys the urine flow, clearances of PAH and creatinine, as well as the amount of sodium excreted, but the effect was weaker on the experimental side than on contralateral side. With $0.1\;{\mu}g/kg/min$., two cases among 6 experiments showed marked diuresis, two cases no apparent effect, and another two marked antidiuresis on the experimental kidney, whereas the contralateral kidney exhibited antidiuresis in all cases. Further reducing the dose unmasked the diuretic action on the ,experimental kidney. In another series, the effects of isoproterenol on the blood flow distribution within the kidney and on sodium concentration gradient within the kidney tissue were observed. $0.05\;{\mu}g/kg/min$ isoproterenol markedly increased the medullary plasma flow and slightly increased total renal plasma flow and glomerular filtration rate, along with concomitant increase in the amount of sodium excreted and osmolar clearance, and decrease in reabsorption of free water. Sodium concentration gradient markedly decreased in the experimental kidney, reaching 2/3 of the value observed in the contralateral kidney at the papilla. It is thus concluded that isoproterenol exerts a diuretic action, when infused directly into a renal artery, and the mechanism of the action rests on its hemodynamic action, substantiated as the increase in glomerular filtration and in the medullary blood flow, resulting in washout of hyperosmolality produced by the coutercurrent multiplier system.

• Journal of Chest Surgery
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• v.31 no.4
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• pp.402-408
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• 1998

A 56-year old female underwent total aortic arch replacement March 1995, because of an expanding chronic Debakey type I aortic dissection. This aortic dissection had an intimal tear at the origin of the right carotid artery. Retrograde and antegrade propagation of dissection resulted in aortic arch blood flow separation and expanding pseudolumen to the abdominal aorta. Sudden anuria(ARF) developed 3 hours later postoperatively and renal doppler ultrasonography and aortography showed diminished blood flow of renal arteries. We performed balloon aortic dilatation but failed. She could be restored good renal flow after intimal flap fenestration resection and thrombectomy of the abdominal aorta. This patient could be discharged in a state of mild CRF after 2 months of ICU care for respiratory and renal failure.

• The Korean Journal of Physiology
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• v.19 no.1
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• pp.25-33
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• 1985

Renal arterial infusion of renotropic agents has been a very useful technique in the renal function studies. This type of experiments have usually been conducted in the large animals such as dogs and sheep. In these animals a catheter can be placed in the site without much disturbances of renal blood flow. Rabbits as an experimental model, however, caused a disturbances of renal blood flow by a catheterization of renal artery by its properties. Therefore we have developed a new technique that allows a simple and selective access to one side of renal arteries and the other as a control, without any disturbances of renal function. The distance between the both bifurcations of renal arteries on abdominal aorta is about 7 mm. To locate the tip of catheter on one side renal artery, ascending cannulation performed via femoral artery was done. We did an experiment with the technique to clarify the effect of calmodulin inhibitor on the renal function. One of the phenothiazine derivatives, trifluoperazine known as a powerful calmodulin inhibitor. Trifluoperazine, actual dose ranges of $2.76-5.20\;ug\;{\cdot}\;kg^{-1}\;{\cdot}\;min^{-1}$, increased urine volume and glomerular filtration rate significantly. Significant increases in urinary excretion of sodium, chloride and potassium were found. Fractional excretion of sodium and free water clearance increased significantly. These data suggest that this new technique is very useful in field of renal physiology and that striking effect of trifluoperazine on the renal function may be caused by increasing the renal hemodynamics, and by the inhibition of sodium, chloride and potassium reabsorption in the renal tubules.

• Journal of computational fluids engineering
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• v.16 no.4
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• pp.84-91
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• 2011

Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics through arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.469-476
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• 2011

Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics though arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.

• The Korean Journal of Pharmacology
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• v.12 no.1
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• pp.31-44
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• 1976

It has been reported that many of the effects of digitalis glycosides could be mediated partly through the central nervous system. In this study the effects of ouabain given directly into the lateral ventricle of the brain on the renal function of the rabbit were investigated. Intraventricular ouabain elicited antidiuresis in doses ranging from 0.1 to $3\;{\mu}g$, exhibiting a rough dose-response relationship, and decreased the renal plasma flow, glomerular filtration rate and urinary excretion of sodium and potassium, concomitant with the decrease of urine flow. These decreases in urine flow, excretory rate of electrolytes significantly correlated with the decrease in renal plasma flow or glomerular filtration rate, suggesting that the antidiuresis might have been induced by the hemodynamic changes. Intravenous ouabain in a dose of $1\;{\mu}g$ did not affect the renal function. Systemic blood pressure as well as cardiac activity was not affected by the intraventricular ouabain. Effects of the intraventricular ouabain on renal function were abolished by the intravenous phentolamine-pretreatment but not affected by intraventricular phentolamine-pretreatment. Neither vasopressin infusion nor hydration did affect the renal effects of intraventricular ouabain. From these observations, it is suggested that the antidiuresis of intraventricular ouabain is induced by the increased sympathetic influence to the kidney.