Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Functional significance of renal artery stenosis (RAS) was assessed by 99Tcm-DTPA radionuclide scintigraphy, using the mean parenchymal transit time (MPTT) of the tracer as an index of renovascular disorder. Two groups of subjects were investigated retrospectively: eight normal live kidney donors; and 11 patients with hypertension, six with and five without significant RAS. MPTT was 171 +/- 11 s in the kidney donors, and there was a significantly prolonged MPTT in patients with RAS, 313 +/- 27 s (p less than 0.05). MPTT was also prolonged in three hypertensive patients with intrinsic renal disorders. The advantages and limitations of this technique are discussed. It is concluded that prolongation of MPTT can detect functionally significant renovascular disorder without pharmacological challenge.
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PMID:Validity of the mean parenchymal transit time as a screening test for the detection of functional renal artery stenosis in hypertensive patients. 268 42

Dilevalol, the R-R optical isomer of labetalol, is a nonselective beta adrenergic blocking drug with selective beta-2 agonist properties. In a double-blind, crossover study the renal function effects of dilevalol were compared to placebo in 12 normotensive elderly volunteers before and after single dose administration. In addition, chronic treatment (greater than 4 weeks) effects of dilevalol were determined in eight elderly patients with mild to moderate essential hypertension. Renal function was determined by plasma disappearance curves from single injections of 99mTc-DTPA and 131I-orthohippurate. In both study populations renal function tests commenced two hours after dosing at expected peak plasma levels of dilevalol. Normotensive volunteers had an acute decrease in glomerular filtration rate of 10.3 ml/min, which was significant (P less than 0.05), while hypertensive patients had no change in glomerular filtration rate. There were no significant changes in other parameters of renal function measured. In the hypertensive elderly dilevalol treatment resulted in significant reductions, 18 and 19 mmHg respectively, of systolic (P less than 0.01) and diastolic (P less than 0.001) blood pressure. Heart rate was reduced by 5 beats per minute, and the change was not statistically significant. Dilevalol appears to be an excellent agent for treatment of hypertension in the elderly hypertensive patient, and does not change renal function when administered chronically to the hypertensive patient. Small but significant decrements in glomerular filtration rate occur with acute administration to normotensive volunteers.
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PMID:The renal function and blood pressure effects of dilevalol in the normotensive and hypertensive elderly. 276 Feb 54

Critical factors determining the renal handling of 99mTc-dimercaptosuccinic acid (DMSA) are protein binding in plasma and the renal 99mTc-DMSA extraction efficiency. Comparison of the count rate over soft tissue with that over the cardiac blood pool about 1 h after injection demonstrated that 99mTc-DMSA is not exclusively an intravascular label. 99mTc-DMSA was 76% protein bound in plasma as demonstrated by HPLC and gel filtration. Assuming that the 24% that is not protein bound is filtered at the glomerulus, the renal extraction efficiency of 99mTc-DMSA by glomerular filtration is about 5%. Since the total renal extraction efficiency was also found to be about 5%, the majority of the activity that becomes fixed in the renal cortex arrives there as a result of filtration followed by tubular reabsorption rather than by direct extraction from peritubular blood. However, discordant changes in DMSA and DTPA uptake induced by captopril in renovascular hypertension (RVH) suggested that a minority of uptake was by direct peritubular extraction. This kinetic model was supported by indirect measurement of protein binding and extraction efficiency based on the kinetics of 99mTc-DMSA disappearance from plasma and kinetics of uptake in the kidneys. Furthermore, differential functional studies based on 99mTc-DMSA and 99mTc-DTPA before and after captopril in patients with RVH due to unilateral renal artery stenosis confirmed filtration followed by tubular reabsorption as the predominant route for DMSA uptake by the kidney.
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PMID:Two routes for 99mTc-DMSA uptake into the renal cortical tubular cell. 255 16

Two hundred nine hypertensive patients with high stimulated plasma renin levels were screened for renovascular hypertension using Tc-99m DTPA renal scintigraphy. Differential glomerular filtration rate (Diff-GFR) was obtained by integrating the area under the background-subtracted renogram of each kidney between 1 and 3 minutes. 50 patients who also had undergone selective renal angiography were divided into four groups according to Diff-GFR contribution by one of the kidneys. If one kidney contributed 45-50% of total GFR, this was regarded as normal. A Diff-GFR of less than 45% was very considered to be very suggestive of renovascular hypertension in the appropriate clinical setting, while a Diff-GFR of less than 20% indicated that the renal artery might not be amenable to successful balloon angioplasty. Diff-GFR following balloon angioplasty closely reflected the early clinical response of the patients--and in some cases progressive Diff-GFR improvement was observed several months later. Diff-GFR as a scintigraphic criterion for renovascular hypertension has a sensitivity of 93%, specificity of 74%, and accuracy of 85%.
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PMID:Differential glomerular filtration rate in diagnosis of renovascular hypertension and follow-up of balloon angioplasty. 293 97

In 60 patients with hypertension and unilateral renal artery stenosis (URAS) radio-hippuran renograms were performed before and 6 weeks after anatomically adequate percutaneous transluminal angioplasty (PTA). Two characteristics of the renographic curves have been analyzed: the difference in time to peak (DTP) between the affected and contralateral kidneys, which would be expected to be positive in blood flow impairment, and the relative hippuran uptake (RHU) in the second minute by the affected kidney as compared with the total uptake by both kidneys: this would be less than 50% in the case of stenosis. Before PTA, both variables were predominantly abnormal. The DTP did not predict the blood pressure response to PTA. The group of patients with a RHU between 25 and 45% comprised all cured patients and predicted a more favorable response of the blood pressure than a RHU of less than 25% and especially more than 45% which group contained 83% patients whose blood pressure failed to respond after PTA. After PTA the DTP did normalize in the majority of patients, but this was not related to the blood pressure response. The RHU increased in patients in whom it had been low initially, but frequently remained low (less than 45%). The increase of the RHU was significantly higher in patients with a favorable blood pressure response. Pretreatment with captopril did intensify the abnormal curves of hippuran and of DTPA renograms in 6 patients with URAS who did respond favorably to PTA. There was no such deterioration in 2 patients whose blood pressure did not change sufficiently after PTA or in 4 patients without renal artery stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Renography: prediction of blood pressure after dilatation of renal artery stenosis. 294 16

The renal circulation of patients with essential hypertension and renovascular hypertension was evaluated using 99mTc-DTPA. The first renal peak count (the first Cmax; FCmax), time phase distribution (the first Tmax; FTmax), and blood velocity (the FCmax/FTmax) were calculated by digital imaging. This yields a visual image of the renal circulation. We consider that the increase in the renal first pass blood flow in patients with essential hypertension is best observed pixel by pixel. The FCmax and FCmax/FTmax images before and after treatment by percutaneous transluminal renal angioplasty in patients with renovascular hypertension clearly show its therapeutic effect. The FI technique, therefore, has the advantage that it can be performed at the same time as the conventional routine examinations of renal function. This makes it very useful clinically.
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PMID:Evaluation of renal first pass blood flow with a functional image technique in hypertensive patients. 296 58

The preparation, application and clinical usage of 99mTc-mercaptoacetyltriglycine, MAG3, a tubular secreted compound, is described in the first 225 patients in a phase III study. Image quality, relative renal function, and renal transit times were compared with a 4 fold greater administered activity of 99mTc-DTPA in 11 patients. Correlation coefficients of 0.94 for relative function, 0.83 for parenchymal transit time index and 0.82 for whole kidney transit time index were found. Frusemide responses were similar. 99mTc-MAG3 is an efficacious radiopharmaceutical for routine renal radionuclide studies, giving excellent image quality in patients with hypertension, poor renal function, obstructive nephropathy or a renal transplant.
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PMID:Clinical experience with 99mTc-MAG3, mercaptoacetyltriglycine, and a comparison with 99mTc-DTPA. 297 19

Renal scintigraphy with technetium Tc 99m succimer (DMSA) and technetium Tc 99m pentetate (DTPA) was used to study 80 hypertensive pediatric and adolescent patients. Renal abnormalities such as asymmetry of function, size, or shape were identified in 13 patients. Both excretory urography and technetium Tc 99m pentetate studies were successful in detecting 54% of the abnormalities in patients studied; technetium Tc 99m succimer identified 92%. The accuracy of the latter was 96%, with a specificity of 97%. The ability of technetium Tc 99m succimer renal scintigraphy to identify accurately the presence or absence of renal abnormalities warrants its inclusion in the initial examination of pediatric and adolescent patients with hypertension.
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PMID:Hypertension in children. Increased efficacy of technetium Tc 99m succimer in screening for renal disease. 298 28

A 99mTc-DTPA radiorenographic study, supported by excretory urography, blood chemistry and eventually histology was performed on 8 chacma baboons (Papio ursinus) after surgical induction of unilateral renal vein hypertension. Frequent sequential repeat renograms during 6 post-operative months detected fluctuating renal behaviour but did not reveal typical course of the disease. Neither did any one of the radiorenographic parameters (TP, T1/2, FF, relative clearances and perfusion) prove to be more sensitive than the others in detecting abnormalities. Initial microscopic or macroscopic haematuria and proteinuria in general eventually cleared up. Light microscopy demonstrated only mild abnormalities. The effects of venous occlusion of the kidney and the prognosis seemed to be variable as was reflected by radiorenography.
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PMID:A progressive radiorenographic (99mTc-DTPA) presentation of surgically induced renal vein hypertension in baboons. 304 6

DTPA functional renal camera scintigraphy (DTPA-FS) was performed in 220 patients with moderately severe and severe hypertension after an initial 7-14-day Captopril + thiazide-type diuretic treatment. If, comparing it with the DTPA-FS prior to treatment, appearance or increase of a side difference were observed and it was also indicated by the clinical picture, nephroangiography was performed. Using this method, 15 cases of unilateral, 3 bilateral renal arterial stenoses were recognized, and in one case restenosis was diagnosed, in all cases of positive DTPA-FS with Captopril. In negative case of DTPA-FS sensitized with Captopril, there was no positive angiographic finding. The method of DTPA-FS performed under Captopril effect is considered to be a simple, harmless, specific out-patient examination for screening genuine renovascular hypertension. To perform several angiographies likely to be negative can be avoided by this method. The hypotensive effect of Captopril may, at the same time, be a useful guide in differentiating patients with renovascular hypertension being suitable most of all for surgical intervention or angioplasty.
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PMID:A new examination method for detecting renovascular hypertension: functional DTPA renal scintigraphy sensitized by captopril. 307 99


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