Partial obstruction of the left ureter was created in seven dogs. Renal function was studied 3 weeks later. Total renal blood flow (RBF) and intrarenal blood flow distribution were studied using the microsphere technique. Glomerular filtration rate (GFR), effective renal plasma flow (CPAH) and the excretion of sodium and osmolar ...

The aim was to study differences in filtration driving forces and glomerular filtration rates between superficial and deep nephrons when urine flow rate was altered at the macula densa region. In young rats stop-flow pressures and single nephron glomerular filtration rates (SNGFR) were measured in the superficial proximal tubules and ...

A new method of unilateral renal denervation (DNX) was developed in dogs by rapidly injecting 6-hydroxydopamine (6-OHDA) into the renal artery with simultaneous collection of the venous effluent to avoid systemic effects. The procedure induced a 93.1 +/- 2.7% destruction of the adrenergic innervation as assessed by a histochemical fluorescence ...

It has been concluded that tubulo-glomerular feedback mechanism is triggered by changes in NaCl concentration ([NaCl]) at the macula densa. This conclusion is based on the demonstration that changes in filtration rate produced during retrograde perfusion of the loop of Henle depend upon the perfusate [NaCl]. Experiments were performed to ...

Partial obstruction of one ureter was created in newborn rats. The weights and blood flows (using the 86Rb-extraction method) of the cortex and outer and inner medulla were examined nine weeks later, i.e., in the adult. The obstructed pelvis was found to be enlarged 7-fold. The whole kidney blood flow ...

Di-(2-ethylhexyl)phthalate (DEHP), a plasticizer used for polyvinylchloride polymers, has been reported to leach from blood transfusion bags and the plastic material in hemodialysis units into the blood. Phthalate esters are known to be hepatotoxic and teratogenic in experimental animals. Reports on the distribution and metabolism of DEHP indicate that the ...

Intrarenal blood flow distribution was measured in normal and hypoperfused dog kidneys by xenon-133 washout measurement in one kidney vary slightly in contrast to those done in different kidneys. In normal kidneys the ratio of compartment I (CI) flow to whole renal flow -- i.e., the CI fraction--as measured by ...

Hypertension (210 mm Hg), hyponatremia, hypochloremia, and hypokalemia were observed in an 11-day-old infant. After electrolyte repletion, blood pressure rose to 320 mm Hg in spite of administration of antihypertensive drugs. The child died of a massive cerebral hemorrhage on the 17th day of life. At autopsy, the left renal ...

The role of the kidney as a possible source or as activator of inactive renin was studied in 22 patients with Essential Hypertension (EH) and in 20 patients with Unilateral Renal Artery Stenosis (RAS). Active and inactive renin (trypsin activation) were measured in blood samples taken simultaneously from both renal ...

A ureteroneocystostomy (UNC) was carried out on 32 dogs. A standardised measurement of flow across the ureterovesical anastomosis revealed a significant obstruction on the day of the operation itself and on the first 5 days after the operation. On the 1st, 7th and 28th day after the operation there was ...

Micropuncture and microcatheterization studies have been used extensively to investigate the pathophysiologic alterations in renal function induced by urinary tract obstruction. The present isolated tubule microperfusion studies were designed to examine the intrinsic alterations in segmental nephron function induced by 24 h of bilateral (BUO) and unilateral (UUO) urinary tract ...

Continuous measurements of local blood flow were performed by means of short pulse heated miniature thermistors. Results obtained in rat cerebral cortex or skeletal muscle show good stability of the recordings and the sensitivity of the system to phasic changes in local blood flow. Experiments on perfused rabbit kidney support ...

The kidney of Clarias batrachus is distinguished morphologically into head, trunk and mesonephric lobes. All parts of the kidney are provided with heterotopic thyroid follicles. The study of serial sections indicates that they are migrated from Pharyngeal region along the blood vessels. They are present in the form of clusters ...

Previous studies from our laboratory have already shown that pretransplant blood transfusions from third-party donors significantly prolong kidney allograft survival in mismatched unrelated immunosuppressed dogs. In the present study, a similar effect was found in related donor-recipient pairs mismatched for two haplotypes (P less than 0.05); no significant effect was ...

A concept of a kidney uptake coefficient (UC) of 131I-o-hippurate was developed by analogy from the corresponding kidney clearance of blood plasma in the early period after injection of the hippurate. The UC for each kidney was defined as the count-rate over its ROI at a time shorter than the ...

Simultaneous measurement of glomerular flow by 15 mum microspheres (Ms) and postglomerular capillary flow by 125I-iodoantipyrine (I-Ap) suggest that about 10% of total RBF flow inward through the entire cortex in the postglomerular capillaries of the dog kidney. This flow fraction might be variable (Clausen et al. 1978, 1980) and ...

The membrane attack complex (MAC) of the complement system was localized in both glomeruli and peritubular regions of 22 kidneys manifesting systemic lupus erythematosus (SLE) nephritis. A similar distribution was observed for immune complex markers (IgG, Clq, and C3) and MAC in glomeruli, although the deposits of MAC were more ...

1. A new method, based on the transit time of omicron-iodohippurate sodium (Hippuran) through the kidney, is proposed as an accurate non-invasive means of measuring the intrarenal flow distribution in man. 2. Data from [123I]Hippuran gamma-camera renography are utilized in this method which employs region of interest selection, deconvolution, cross-correlation ...

Regional blood flow to the kidneys was measured in 6 ewes by injecting carbonized microspheres (15 micrometer +/- 5) labeled with 85Sr into the left ventricle. There was no significant (P greater than 0.25) difference in the mean arterial pressure before and after injection of the microspheres. Normal values of ...

The early changes in tubular reabsorption, glomerular filtration, blood flow and sodium excretion brought about by uranyl nitrate were investigated in isolated, blood-perfused dog kidneys during water diuresis. No significant changes in urine volume were observed; the decrease in fluid reabsorption was counterbalanced quantitatively by a reduction in glomerular filtration ...

Skimming could result in erroneous estimation of renal cortical blood flow distribution as measured by microspheres. Skimming of microspheres with diameters 10, 12, and 15 micrometers and red blood cells was therefore studied in a model in which an interlobular artery and its first arteriolar branch were simulated by 80- ...

1 Chlormethiazole was used as a basal sedative for patients undergoing angiographic procedures. 2 Blood samples were drawn opportunistically to examine chlormethiazole extraction across liver, lungs and kidney. 3 Extraction across liver was typically 70-80% and apparently unrelated to input concentrations. Evidence for extraction across lung and kidney was inconclusive ...

1 Theophylline inhibits the enzymatic formation of purine nucleosides, among these adenosine (dephosphorylated adenosine 5'-monophosphate), in kidney and brain of the rat. 2 Some pharmacological effects of theophylline on regional blood flow and electrophysiological activity of the nervous system may be caused by inhibition of the endogenous formation of adenosine.

1. We investigated the role of calcium and albumin on the perfusate flow in isolated perfused rat kidneys. The initial perfusion medium was Krebs-Henseleit bicarbonate solution with 1.82 mm-calcium without albumin. Perfusate flow autoregulation occurred above 100 mmHg.2. Raising albumin concentration to 20 and 60 g/l. abolished autoregulation and increased ...

In the anaesthetized dog total renal blood flow (RBF) and its intrarenal distribution were investigated by the radioactive microsphere technique under control conditions and after various experimental interventions. (i) In five control series performed within the last four years, there was a small but significant scatter in total RBF, due ...

The acetylcholine induced contralateral renorenal vasomotor reflex has been re-examined. In dogs under pentobarbital anaesthesia blood flow of the contralateral kidney as measured by electromagnetic flow probe did not change after an infusion or bolus injection of Ach. Basal sympathetic nervous activity of the contralateral kidney increased only slightly and ...

The effector mechanisms which constitute the efferent limb of the tubuloglomerular feedback system were examined after the administration of benzolamide, a carbonic anhydrase inhibitor, which decreased proximal tubule fluid reabsorption by approximately 8 nl/min and transiently increased delivery of fluid out of the proximal tubule. Since benzolamide administration resulted in ...

The perfusion of the heart, kidneys, adrenals, stomach, intestines, brain and musculature under normobaric hyperoxia was studied in anaesthetized mini pigs using radioactively labelled microspheres. After a 2-hour control period using room air, the influence of normobaric hyperoxia on the perfusion of the organs was measured at 2-hour intervals. A ...

All of these results indicate that the isolated rabbit kidney, perfused either with free-cell media or with whole blood, shows marked functional deficiencies and cannot be considered a reliable preparation. The former media do not induce vasoconstriction but are unable to insure a correct cations reabsorption, while the latter causes ...

Distal renal tubular acidosis has been thought to be the consequence of an impaired ability to maintain a large pH gradient between distal nephron urine and blood. Recent evidence suggests that the classification of deranged distal nephron acidification requires expansion. These mechanisms whereby the urine is acidified in the distal ...

We studied the mechanism of elevated vascular resistance in 34 dogs with unilateral hydronephrotic kidneys. Neither an alpha-receptor blocking agent nor angiotensin II-antagonist reversed renal blood flow reduction 7 hr, 1, 2, and 3 weeks after complete unilateral ureteral ligation. We conclude that blood flow reduction is the same in ...

Prostacyclin is a potent vasodilator and the most potent inhibitor of platelet aggregation yet discovered. A possible role for prostacyclin in the harvesting of kidneys in experimental canine transplantation has been investigated. Prostacyclin gives a 52.6% increase in renal blood flow prenephrectomy despite inducing a 23% drop in mean arterial ...

The local, direct effect of endogenous angiotensin II (AII) in the isolated, perfused rat kidney was studied in an "open-circuit," single-pass preparation perfused at a constant pressure with an artificial solution containing 6.5% bovine albumin in Krebs-Ringer solution. After the addition of purified renin substrate (tetradecapeptide, 3 to 5 X ...

The distribution of 15-micron microspheres was measured in rat kidneys before and after the animals had undergone either isovolemic hematocrit increase or isovolemic hematocrit decrease. Raising the systemic arterial hematocrit from 46 +/- 1% (mean +/- SEM) to 59 +/- 1% caused a significant decrease in the rate of urinary ...

Previous reports suggest the value of renal decapsulation in the prevention of renal failure after acute ischemia. It has been suggested that this response is due to a release of "compartmental" pressure resulting in increased blood flow to the decapsulated kidney. Ten dogs were evaluated following 90 minutes of renal ...

Variations in the distribution of different size microspheres trapped within an organ depend upon regional variations in delivery or trapping of different size spheres. We have determined the intrarenal distribution of trapped 9 mu and 15 mu spheres, as well as their nontrapping and release in dog kidneys. More 15 ...

The paper presents the possibilities of achieving regional renal hypothermia by rinsing the kidney venous system with a cooling solution. The cooling solution flows in and out of the kidney venous system through a specially constructed catheter with two lumens while the kidney is deprived of its blood flow. This ...

Furosemide administration results in an increase in blood flow through the prostaglandin system by causing the release of arachidonic acid from a small pool of lipid stores from the kidney without affecting the total arachidonic acid concentration in the blood. The stimulus for arachidonic acid release from the kidney depends ...

Distribution of intrarenal blood flow has been measured in genetically hypertensive (GH) and normotensive (N) rats (aged 17--23 weeks) by a 133Xe washout technique without opening the abdominal cavity. Three different specific flow compartments were found in the rats. The distribution of the intrarenal blood flow to the fast compartment ...

The renal blood flow and related variables were assessed with a dye dilution technique in conjunction with angiography of the enlarged kidney in 13 patients with unilateral disease, hypoplasia or aplasia of one kidney. The total renal blood flow, the width of the arteries, the kidney area, the vascular volume ...

Tubular reabsorption was inhibited in isolated dog kidneys by the progressive substitution of plasma chloride by sulphate. In the absence of antidiuretic hormone activity, urine output remained unchanged owing to an equivalent decrease in glomerular filtration rate. This equilibrium was demonstrated under conditions of "saline natriuresis" and was not disturbed ...

The effects of chronic blockade of single kidney tubules on glomerular capillary pressure (GCP) and blood flow were examined in anesthetized rats. Tubule blockade with castor oil for 24 h decreased GCP from 48.0 +/- 3.8 to 39.5 +/- 4.7 mmHg (P less than 0.001). The full decrease in GCP ...

The influence of microsphere size upon the estimation of cardiac output (CO), renal blood flow (RBF) and its cortical distribution (ICBFD) was evaluated by simultaneous injection of 8.5 +/- 0.8 micrometer (SD) and 12.7 +/- 1.7 micrometer (SD) spheres in control conditions and after hemorrhagic hypotension (HH rats). The values ...

Differences in the rate of renin release by superficial and deep areas of the cat kidney cortex were studied in vitro and in vivo. Renin release in vitro by outer cortical slices was significantly higher than by their inner counterparts: 19.6 +/- 2.3 vs. 12.8 +/- 1.95 ng angiotensin I-h-1-mg ...

Disparate reports on intrarenal blood flow distribution prompted a direct comparison between microspheres (Ms) and inert diffusible tracers (DT). The "tissue sampling technique" for estimating local flow with DT (Kety) was adapted for the dog kidney, using 125I-iodoantipyrine (1-Ap) and tritiated water (THO). Ms (15 micron) were injected 2-3 min ...

A method is described for measuring distribution of intrarenal blood flow in anesthetized rats by a xenon-133 washout technique that avoids the trauma of opening the abdominal cavity and manipulating the kidney. Precise delivery of the tracer to the kidney and fine collimation of the radiation reduces the amount of ...

In anesthetized vagotomized dogs with renal arterial pressure constant, carotid sinus hypotension (BCO) caused a reflex rise in systemic arterial pressure, a fall in renal blood flow, and a similar increase in renin release from both kidneys. Unilateral alpha-adrenoceptor blockade with phenoxybenzamine resulted in an increase in basal renal blood ...

Halothane-induced changes in renal function have generally been attributed to alterations in systemic hemodynamics, sympathetic tone, and various hormones. Studies were performed to determine whether halothane directly affects the kidney. Twenty-one canine kidneys were perfused in vitro utilizing hemodilution, pulsatile flow, and membrane oxygenation. Temperature and arterial blood-gas variables were ...

Renal ischaemia produced by clamping of the blood vessels in situ for periods of 10 to 150 minutes resulted in a progressive depletion of the total content of adenylates in the kidney tissue (sigma ATP, ADP, AMP). Initial dephosphorylation of ATP and ADP, resulting in further catabolism of AMP to ...

In the presented series of experiments, stroma-free hemoglobin solution (SFHS) was used as a perfusate for extracorporeal perfusion of kidneys and for exchange transfusion. It was shown that SFHS was adequatly oxygenated both as perfusate during the extracorporal perfusion and in the lungs after the blood exchange. Furthermore, there was ...