131I Hippuran Research Articles

Validity of renal split function by single probe renography in hypertensive patients

Single kidney function was determined both by single probe renography (131I hippuran) and gamma camera scintigraphy (99Tcm DMSA) in the sitting position in 42 consecutive patients who were referred to renography as a part of the workup of their hypertension. The positioning of the detectors turned out to be satisfactory in 83 per cent of the patients when compared with the determination of the split function at scintigraphy. This might be explained by the small 100 per cent isocount area of the probe (avoiding the effect of mobile kidneys) and by the 4-channel localization system.

Alternating Use of 123I and 131I Hippuran for Routine Postoperative Monitoring of Transplanted Kidneys is Impracticable

During a 7-week period 123I hippuran was used instead of 131I hippuran for all renographies of transplanted kidneys on Wednesdays. Only in well functioning grafts with a diuresis above 2 ml/min during the examination a scintigraphic improvement of renal and upper urinary visualization was obtained. It is concluded that alternating routine use of the expensive 123I hippuran in control of renal grafts cannot be recommended.

Changes in renal uptake of Tc-99m methylene diphosphonate (MDP) in stone-forming rats.

A pyridoxine (vitamin B6)-deficient diet in rats was used as a model of early renal lithiasis to find out if "stone-formers" could be identified from control animals by differences in the biodistribution of Tc-99m MDP. The mean renal uptake of this agent at 3 hours was about 70% higher in test animals than in controls, but there was considerable overlap between the upper limits of the normal range and lower values in "stone-formers." If these results were valid for humans, the metabolic abnormality in males with early stone-forming disease could not be identified with certainty by in vivo measurements of Tc-99m MDP renal uptake alone. However, the skeletal uptake of MDP in the "stone-forming" animals was depressed by 28 to 35%, compared with control rats. Consequently, the renal to skeletal MDP concentration ratio was invariably elevated in "stone-formers" beyond the 95 percentile normal range. Unexpectedly, 76% of the pyridoxine-deficient animals had a higher accumulation of MDP in the myocardium than the upper limit of the normal range. The pyridoxine-deficient diet induced no remarkable early changes in the biodistribution or renal clearance of I-131 Hippuran.

Experimental drug-induced changes in renal function and biodistribution of 99mTc-MDP.

Increased renal uptake of 99mTc methylene diphosphonate (MDP) was observed irregularly in rats after methotrexate, vincristine or gentamicin, administered separately. Cisplatin regularly induced a dose-related increased MDP uptake which correlated with the degree of tubular damage histologically. The augmented MDP renal uptake was not consistently accompanied by a decreased clearance of simultaneously injected I-131 Hippuran, particularly at lower drug dose levels. This observation agreed with previous evidence that the mechanisms of tubular transport of diphosphonates and organic acids like Hippuran are different. At higher dose levels, the augmented MDP uptake was accompanied by increased renal calcium, hypophosphatemia, elevated serum urea nitrogen and creatinine, and only occasional, mild hypercalcemia. The magnitude of the increased renal uptake of MDP observed could not be explained by alterations in iron metabolism or by dehydration. Drug-induced renal retention of MDP by a factor of 2 or more above normal appears to be a useful indicator of tubular damage when other parameters of renal function are sometimes normal.

Renal cyst epithelial transport in non-uremic polycystic kidney disease

Renal cyst epithelial transport of organic molecules was investigated during three separate cyst drainage procedures in a non-uremic patient with polycystic kidney disease (PCKD). Following constant intravenous insulin infusion, four of eight sampled cysts achieved concentrations exceeding those expected by glomerular filtration alone. Likewise, cyst concentrations of the filtered radionuclide Tc DTPA were up to 3.7 times simultaneous plasma levels. Both PAH and I-131 hippuran accumulated in all cysts suggesting intact tubular secretory mechanisms. Quantitative amino acid levels in two proximal nephron cysts were identical to serum. Since concentrations of inulin, DTPA, and amino acids exceed levels expected if cystic nephrons had normal glomerular filtration and tubular reabsorptive properties, other mechanisms are likely. Simple diffusion across altered epithelial surfaces could partially account for the observed cyst concentrations of each organic molecule and, by ion trapping, contribute to progressive cyst growth in PCKD.

Renal Allograft Recovery Subsequent to Apparent "Hyperacute" Rejection Based on Clinical, Scintigraphic, and Pathologic Criteria

An unusual case is described in which in spite of clinical, scintigraphic and histologic findings strongly supportive of a diagnosis of "hyperacute rejection," recovery of renal function occurred. These findings are in contrast to the current literature in which it is generally accepted that a renal allograft showing neither pertechnetate transit nor hippurate concentration warrants allograft nephrectomy irrespective of the etiology. Scintigraphic evaluation included both dynamic studies after a bolus administration of Tc-99m pertechnetate and serial renogram collections after the intravenous administration of I-131 Hippuran.

Interpretation of interspecies differences in the biodistribution of radioactive agents

The biodistribution of some radioactive agents is anomalous and unpredictable from one species to another. However, many agents follow a general pattern of rapid clearance from the blood and total body in small rodents, intermediate clearance in the dog and monkey and slower clearance in man. A major determinant of this interspecies difference is the shorter mean circulation time (blood volume/cardiac output) in smaller animals. To permit comparisons between mammals of varying size, many physiological and metabolic parameters, and stable drug effects have been expressed as power functions with exponents less than 1 (rather than linear functions) of body weight W, or body surface area. Frequency functions such as heart and respiratory rates have been correlated with negative power functions of body weight. The plasma clearances of chemotherapeutic agents in different species has been successfully normalized by altering the time dimension according to power functions of body weight. A similar procedure has been explored to normalize blood and total body clearances of various diagnostic radioactive agents in animals and man. Time equivalent units were derived from W/sup 33/ animal / W/sup 33/ man. The method failed, however for agents with a predominantly intracellular localization or undergoing active cellular transport (suchmore » as T1-201 or I-131 Hippuran). Nonetheless, this approach appears useful in distinguishing interspecies variability merely due to body size from interspecies metabolic variations.« less

Post transplant acute renal failure: a review.

Post transplant acute tubular necrosis (ATN) is responsible for approximately 90% of acute renal failure episodes occurring within the first few weeks following renal transplantation. This phenomenon is observed in 34% of cadaver transplant recipients and 9% of those with live donor kidneys. Although the exact cause of post transplant ATN remains unknown, the following factors are thought to be associated with a higher incidence of ATN: 1) donor hypotension, 2) prolonged "warm ischemia time", 3) increased vascular resistance with poor perfusate flow, 4) presence of "ligandin" or excess lactate in the renal perfusate, 5) reduced allograft blood flow, 6) cold lymphocytotoxins in the patient's serum and 7) administration of nephrotoxic drugs particularly to the hypovolemic graft recipients. Therapeutic maneuvers such as hydration of the donors and recipients, harvesting the kidneys from heart beating cadavers, donor pretreatment with massive doses of corticosteroids and alpha-adrenergic blocking agents and warming of the graft immediately after vascular anastomosis, seem to reduce the incidence of ATN. Since the management differs significantly, post transplant ATN has to be distinguished from other causes of acute renal failure such as the renal artery thrombosis, hyperacute rejection and obstruction of the urinary tract. The tests which are of use in the differential diagnosis include, 131-I Hippuran renogram, transplant ultrasound, renal angiogram, retrograde pyelogram and renal transplant biopsy. Patients with established ATN should undergo every other day dialysis, under low dose or regional heparinization, until the creatinine clearance improves to 20 ml/min. The dose of azathioprine has to be reduced to prevent bone marrow toxicity. Even though there are short term disadvantages, the post transplant ATN does not appear to exert any detrimental effects in the long run. However, this issue remains controversial in the published reports.

Vesicoureteral Reflux in the Primate IV: Does Reflux Harm the Kidney?

It has been said that vesicoureteral reflux causes renal scarring because of intrarenal reflux. We studied reflux in the monkey because of its similarity to man, especially in regard to the incidence of vesicoureteral reflux and chronic pyelonephritis.High pressure moderate grade reflux was produced and renal function followed by means of quantitative renal camera studies using 131I hippuran. There was no change in renal function from sterile reflux even when intrarenal reflux occurred. When, however, infection was introduced, renal function decreased. We concluded that sterile moderate vesicoureteral or intrarenal reflux does not harm the kidney.

Bladder Wall Dose from Administered Radiopharmaceuticals: The Effects of Variations in Urine Flow Rate, Voiding Interval and Initial Bladder Content

Equations are given for calculating the dose to the surface of the bladder wall for any values of the parameters, urine flow-rate, bladder voiding period and initial content, for any administered radiopharmaceutical with known biokinetics. The necessary relationships which describe the variation in dose to the bladder wall per unit of cumulated activity in contents with increasing volume of contents are given for 31 radionuclides. Two commonly used rental radiopharmaceuticals, 131I Hippuran and 99Tcm DTPA, are used to illustrate the effects of the above three physiological variables on the dose to the bladder wall and it may be concluded that, for radiopharmaceuticals which are rapidly transferred to the bladder, substantial dose reduction can be achieved by optimising these parameters. Thus, where possible, the patient should be well hydrated, the radiopharmaceutical should be administered when the bladder is partly filled and the voiding period should be about 1.5 h.

Bestimmung der131J-Hippuratclearance im Verlaufe der Schwangerschaft

Changes in 131I hippuran clearance were estimated by a non-catheter method, as well as total clearance and clearance of each kidney, in 43 women at various stages of pregnancy and in 13 non-pregnant women who were not using hormonal contraceptives. The results are demonstrated in graph form. The methods used are described in detail. The procedure for determining clearance in separate kidneys is indicated. It was found that clearance values increased up to the 35th and 36th weeks of pregnancy. The difference between the sides that were found corresponds with the previously known difference in the function of the right and left kidneys and ureters.

Renal consequences of irradiation of the spleen in lymphoma patients

The authors have studied the consequences of irradiation of the upper part of the left kidney during treatment of the spleen. Seventy-four patients with lymphoma were entered in the study. They have all been followed up for between three and five years. Renal function was assessed by physical examination, biological tests, intravenous pyelograms and nephrotomographies, isotope scans with 197Hg neohydrin, dynamic studies with 131I hippuran and 99Tcm DTPA. No significant changes have been noted for blood pressure, biological tests or IVP. Eighteen months after irradiation renal tomograms showed cortical atrophy of the superior pole of the left kidney. 197Hg neohydrin started to show reduced uptake of the isotope in the irradiated region of the left kidney by the eighth month. 131I hippuran and 99Tcm DTPA detected abnormalities respectively five and three months after irradiation. No compensatory hypertrophy nor change in the overall kidney function have been noted. In Hodgkin's disease, radiotherapy has proved its efficiency in splenic involvement and the lack of secondary renal side effects. On the other hand, morbidity was shown to occur in 5% of cases after splenectomy. From these data, it is proposed to prefer radiotherapy rather than surgery for splenic treatment.

The effect of urinary obstruction on the results of catheterless divided 131I hippuran clearance studies (author's transl)

During catheterless renal 131I Hippuran clearance studies, the function of each kidney can be calculated from the area integral, which is derived from the total body curve and to segments of phase II of each nephrographic curve measured for 120 seconds after the injection. For this it is assumed that the course of this phase depends entirely on the function of the renal parenchyma and is not affected by other factors such as urinary obstruction. During investigations of obstructed kidneys, considerable discrepancies were found repeatedly between clearances calculated by this method and the operative findings of a paper thin renal parenchyma of the kidney in question. In two cases it has been shown for the first time that there is an unexpected and surprising change in phase II. It follows that urinary obstruction falsifies the results of 131I Hippuran clearance tests, leading to an overestimate of the function of the obstructed kidney.

Validity of 99mTc Dimercaptosuccinic Acid Renal Uptake for an Assessment of Individual Kidney Function

99mTc dimercaptosuccinic acid is a new renal scanning agent that provides a good quality of renal image as a result of preferential cortical accumulation and also makes feasible a quantitative assessment of separate kidney function, correlating well with renal plasma flow obtained from a 131I hippuran renogram of each kidney. By measuring the dimercaptosuccinic acid uptake, the cortical functioning nephrons can be determined independent of the activity from the urinary outflow tract. Such evaluations may replace the conventional split renal function study in which traumatic procedures, such as cystoscopy and ureteral catheterizations, are required. 99mTc dimercaptosuccinic acid scintigraphy causes less discomfort to the patient and can be performed repeatedly and routinely even in children and debilitated geriatric patients.

Non-Invasive Localization of Urinary Tract Infection

New methods to localize the source of bacteriuria were evaluated in monkeys with experimental urinary tract infection. A high level of diagnostic accuracy was obtained with the combined study of antibody-coated urinary bacteria by immunofluorescence, 131I hippuran scintiphotos in the hydropenic state and 67gallium citrate scintiphotos. Unique patterns were found, which differentiate cystitis, ureteritis, pyelonephritis and renal or perinephric abscesses.

99mTechnetium Penicillamine: A Renal Cortical Scanning Agent

99mTechnetium penicillamine, a renal cortical imaging agent, can be used to provide a rapid, safe and non-invasive assessment of renal morphology and the renal vascular supply. Since this agent is not excreted significantly during the imaging procedure cortical scans of high quality can be obtained without image deterioration owing to a superimposed collecting system. These scans, which are clearly superior in anatomical detail to earlier scans using 131I hippuran, can be obtained along with the 131I hippuran renogram when the patient comes to the nuclear medicine department. Herein we demonstrate the anatomical detail it is now possible to achieve by presenting the cortical renal scans and accompanying radiograms from 5 patients with different renal pathology.

Cerebral blood flow in patients with subarachnoid haemorrhage studied with an intravenous isotope technique. Its clinical significance in the timing of surgery of cerebral arterial aneurysm

The cerebral blood flow state has been evaluated in a series of 207 patients suffering from subarachnoid haemorrhage and with proved arterial aneurysms. Particular interest was focussed on 160 in grade I or II according to Botterell. An intravenous isotope method was used with 131-I Hippuran or 99-Tc pertechnetate as indicators. 133 of the 160 patients were operated on. 78 were also examined postoperatively. The radioactivity was recorded by two gamma detectors place bilaterally over the skull. The heights of the curves were taken as an index of the cerebral blood flow. Transit time was determined by dividing the area of the curve by its height. The results showed that even patients with no or slight neurological symptoms could have a depressed cerebral blood flow. Alterations in the blood flow seemed to precede a change in the clinical picture. Postoperatively, most patients had a further decrease in flow, but some others remained unchanged or even improved. With a normal or only slightly disturbed cerebral blood flow in the preoperative period, the morbidity and mortality of intracranial aneurysm surgery was estimated at 8%. For patients with a low preoperative blood flow value, i.e. more than a 40% reduction, the morbidity and mortality was much higher, about 30%. The results indicate that an analysis of the cerebral blood flow status represents an additional diagnostic parameter of great clinical significance, increasing the possibility of predicting to outcome of the operative treatment of an intracranial arterial aneurysm.

Reversible Renal Hypertension Secondary to Renal Arteriovenous Fistula and Renal Cell Carcinoma

A 40-year-old woman with hypertension (179/100) and a massive renal arteriovenous fistula involving most of the right kidney is reported. A 131I hippuran renogram, split urinary function studies and renal vein renins were normal. The renal arteriovenous fistula was removed by total nephrectomy and blood pressure returned to normal. A renal cell carcinoma was found within the fistula. This case confirms the association of renal cell carcinoma with renal arteriovenous fistulas and demonstrates the potential curative effects of nephrectomy for the hypertension associated with it. The normal split function studies, renogram and renal vein renins do not support the concept of secondary hyperreninemia as a causative factor in the hypertension seen with renal arteriovenous fistulas.

Radionuclides in the Diagnosis of Suprarenal Masses

A simple, non-invasive method is described for evaluating suprarenal masses by superimposing images of the perfused reticuloendothelial tissue of the liver and spleen with 99mtechnetium sulfur colloid and the renal tissue with 131I hippuran. The normal anatomic relationship as well as examples of suprarenal pathology is presented.

Kidney depth measurements using a double isotope technique.

Differences in kidney depth, particularly between the two kidneys of an individual patient, may lead to distortions of the renogram owing to attenuation and geometrical factors. A method of assessing the magnitude of these variations was developed. A double isotope technique was used, employing 125-I and 131-I Hippuran, the kidney depth being a function of the ratio of the count-rates from the two isotopes. It was necessary to apply a correction for extrarenal activity, based on a third detector and doubly labelled human serum albumin. The average kidney depth observed was 7.3 cm; in only two cases out of 13 did the difference in depth of the two kidneys exceed 1 cm. It is concluded that when 131-I Hippuran is used the consequent distortion of the renogram is acceptable. With 125-I the distortion may be excessive, even though the contribution of extrarenal activity is then reduced. There was frequently an apparent increase in the depth of activity during the renogram attributable to intrarenal translocation of the tracer.