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Results 451 - 500 of 633
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Doi R - - 1982
The organ distribution and biological half-time of methylmercury were examined in male mice of 3 inbred strains, BALB/c, C3H/HeN and C57BL/6N, and a random-bred strain, CD-1 (ICR), at 6 weeks after birth. Methylmercury chloride was administered intraperitoneally at the dose of 1 mg per kilogram of body weight. At various ...
Finco D R - - 1982
Creatinine and [14C]inulin clearance values were nearly the same during stop-flow and free-flow conditions in the cat. We conclude that glomerular filtration is the sole factor in renal excretion of creatinine in this species. Anatomic (bladder vs kidney) and dynamic (slow vs fast urine flow rate) studies indicated insignificant changes ...
Banks R A - - 1982
1. The time dependent effects of intravenous sodium meclofenamate (6 mg/kg) on blood flow to a variety of organs was studied in the conscious rabbit. 2. After meclofenamate administration, blood flow was reduced in the kidney and adrenal glands and increased in the hepatic artery. The changes were relatively short ...
Ichikawa I - - 1982
The determinants of single nephron glomerular filtration rate (SNGFR) were examined in Munich-Wistar rats by direct glomerular micropuncture during orthograde perfusion of the same nephron's loop of Henle with isotonic Ringer solution at O and 40 nl/min. At the higher loop flow rate, SNGFR decreased significantly by approximately 35% relative ...
Jacobson H R - - 1982
Using in vitro microperfusion of rabbit nephron segments we measured the effects of osmotically induced water flow on net transport of HCO3 and Cl. Measurements were made in superficial and juxtamedullary proximal convolutions and in superficial pars recta. In addition, measurements were taken in the presence and absence (hypothermia) of ...
Horster M F - - 1982
Medullary collecting tubules of rabbits were dissected from the outer zone at different stages of ontogenetic evolution and perfused in vitro. The hydraulic conductivity coefficient (Lp) was measured in the presence of either hypotonic perfusate and isotonic bath or isotonic perfusate and hypertonic bath. Basal Lp (cm s-1 atm-1 10(-7) ...
Appelgren L E - - 1982
The distribution of 14C-chloramphenicol has been studied in new-born pigs with the aid of whole-body autoradiography. In the lung, liver, adrenal cortex, kidney, myocardium, pancreas, thyroid, spleen and skeletal muscle the amounts of radioactivity were higher than that of the blood short time after injection and remained higher than the ...
Ulfendahl H R - - 1982
The intrinsic myogenic hypothesis and the tubuloglomerular feedback mechanism (TGF) give the presently most cherished explanation to the autoregulation of renal blood flow and glomerular filtration rate. A series of experiments was performed on young, normohydrated rats in order to evaluate the importance of TGF as an autoregulatory factor of ...
Müller-Suur R - - 1982
Hitherto, no experimental evidence for the existence of tubuloglomerular feedback regulation (TGF) in juxtamedullary nephrons has been produced. We have developed two micropuncture techniques suitable for the papilla of young rats, which make it possible to investigate TGF in deep nephrons. The first consisted of measuring the tubular flow in ...
Ichikawa I - - 1982
The current notion that tubuloglomerular feedback-mediated regulation of GFR involves selective changes in afferent arteriolar vasomotor tone stems from the familiar finding that manipulation of distal salt delivery alters glomerular capillary hydraulic pressure (PGC). Stop-flow technique, which has been used for this PGC measurement, however, has recently been shown to ...
Wright F S - - 1982
Two aspects of the single nephron feedback response previously observed by us have been reexamined. The first, the effect of modifying the composition of fluid used to perfuse the loop of Henle of a single nephron, was studied in rats by comparing flow-induced changes in stop-flow pressure (PSF) with three ...
Karlberg L - - 1982
Intrarenal blood flow, nephron function and whole kidney function were studied in the recovery phase of acute failure induced by 45 min of warm ischemia. Analyses were made 24 h, 7 days and 28 days after the ischemic insult. At 24 h the total renal blood flow was 4.0 ml ...
Gates G F - - 1982
99mTc diethylenetriaminepentaacetic acid (stannous) is cleared from the blood by glomerular filtration. However, calculation of the glomerular filtration rate has required analysis of serial blood samples drawn over intervals of several hours in order to determine the radionuclide clearance rate. This lengthy procedure can be circumvented by the direct scintigraphic ...
Aperia A - - 1982
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 ...
Ericson A C - - 1982
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 ...
Bichet D - - 1982
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 ...
Briggs J - - 1982
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 ...
Ferrari M - - 1982
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 ...
Fischbach H - - 1982
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 ...
Glorioso N - - 1982
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 ...
Josephson S - - 1982
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 ...
Bijnen A B - - 1982
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 ...
Lindgren A - - 1982
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 ...
Hanley M J - - 1982
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 ...
Sharma R - - 1982
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 ...
Heising J - - 1982
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 ...
Huland H - - 1982
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 ...
Biesecker G - - 1981
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 ...
Clausen G - - 1981
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 ...
Surma M J - - 1981
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 ...
Nizet A - - 1981
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 ...
Reddy V K - - 1981
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 ...
Gruenewald S M - - 1981
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 ...
Mather L E - - 1981
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 ...
Ofjord E S - - 1981
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- ...
Jensen M H - - 1981
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.
Baker S S - - 1981
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 ...
Blantz R C - - 1981
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 ...
László K - - 1981
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 ...
Büsing C M - - 1981
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 ...
Kottra G - - 1981
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 ...
Pacini A - - 1980
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 ...
Arruda J A - - 1980
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 ...
Huland H - - 1980
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 ...
Mundy A R - - 1980
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 ...
Frega N S - - 1980
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 ...
Ackermann U - - 1980
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 ...
Stothert J C JC - - 1980
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 ...
Utley J R - - 1980
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 ...
Butt T J - - 1980
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 ...
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