Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 6-month protocol of oral pulse calcitriol was used in nine uraemic children (2-14 years old) on dialysis who presented with renal osteodystrophy. Calcitriol was administered twice a week, 4 micrograms per dose for patients over 30 kg and 3 micrograms for patients less than 30 kg. Plasma levels of parathyroid hormone, calcium, phosphorus and alkaline phosphatase were carefully controlled during the study. Parathyroid hormone levels decreased by 68% and 56% by the 2nd and 6th months of treatment in seven patients, while they remained unchanged in two patients with focal segmental glomerulosclerosis and massive proteinuria. Eight hypercalcaemic episodes from 77 determinations were observed, all of them recovered after 1 week of vitamin D withdrawal. We conclude that oral calcitriol pulse therapy is a good alternative for renal osteodystrophy in uraemic children. Careful monitoring of plasma parathyroid hormone and calcium is needed during follow-up when using this approach in paediatric patients.
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PMID:Calcitriol oral pulse therapy in children with renal osteodystrophy. 858 20

Mutations in the gene CLCN5 encoding the vesicular chloride channel ClC-5 lead to Dent's disease, an X-linked renal disorder. Dent's disease is characterised by proteinuria, hyperphosphaturia and hypercalciuria, which eventually lead to kidney stones and nephrocalcinosis. As it was unclear how mutations in a chloride channel might cause these symptoms, we and others have generated genetic mouse models to elucidate the underlying pathophysiological mechanisms. We review results obtained from these three mouse models and present new data on endosomal acidification and vitamin D metabolism in ClC-5 knock-out (KO) mice. ClC-5 is expressed in apical endosomes of proximal tubular cells where it co-localizes with endocytosed proteins and the proton ATPase. ClC-5 may provide an electric shunt for the efficient operation of the electrogenic H(+)-ATPase. We confirmed this hypothesis by showing that endosomes from CLCN5 KO mice are acidified at a significantly lower rate than wild-type endosomes. This probably results in the drastic impairment of endocytosis observed in ClC-5 KO mice. Parathyroid hormone (PTH) is filtered into the lumen of the nephron, where it is endocytosed and degraded by proximal tubular cells. The defective endocytosis in ClC-5 KO mice entails an increased luminal concentration of PTH, subsequent stimulation of apical PTH receptors which causes an increased endocytosis of the phosphate transporter NaPi and phosphaturia. We now show that it also results in up-regulation of proximal tubular alpha-hydroxylase that generates the active form of vitamin D from its precursor. We discuss how the primary defect in endocytosis leads via secondary changes in calciotropic hormones to the tertiary symptoms hyperphosphaturia, hypercalciuria and kidney stones.
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PMID:The ClC-5 chloride channel knock-out mouse - an animal model for Dent's disease. 1254 89

Skeletal demineralization is a frequent accompaniment of chronic renal disease and is likely multifactorial. We studied the role of inflammation in stimulating bone resorption in a rat model of glomerulonephritis (GN). Three-week-old Sprague-Dawley rats received either saline (n = 8) or horse spleen apoferritin and lipopolysaccharide (HSA/LPS, n = 8) by intraperitoneal injection, for 6 weeks; afterward, they were observed for either an additional 3 weeks (9 weeks total; n = 4 from each group) or 14 weeks (20 weeks total; n = 4 from each group). Kidneys were analyzed by histomorphometry, and blood and urine samples were obtained to assess bone resorption. Whole-body and isolated femur Dual-Energy X-ray Absorptiometry (DEXA) scans were performed at the end of each study. HSA/LPS-treated animals developed a proliferative GN by 9 weeks, which is associated with proteinuria but no change in renal function. Between 9 and 20 weeks, there was evidence of an increasing interstitial inflammation (1381 +/- 67 interstitial cells/mm(2) at 9 weeks and 1818 +/- 28 interstitial cells/mm(2) at 20 weeks.) There was also evidence of bone resorbing activity as assessed by experimental/control (E/C) < 1.0 at 9 (E/C plasma = 0.66 +/- 0.05) and 20 (E/C plasma = 0.52 +/- 0.04) weeks. Parathyroid hormone (PTH) levels were normal at all time points, and no differences in bone mineral density were found. This model produces not only an immune glomerular/tubular injury, but also a stimulus for bone resorption that is related to objective measures of inflammation severity. The bone resorption is not caused by renal insufficiency, hyperparathyroidism, or steroid therapy. This model will prove useful in other studies of the role of renal inflammation in skeletal disorders.
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PMID:Nonparathyroid hormone-mediated calcium resorption in a rat model of immune glomerulonephritis. 1613 56

Persistent hyperparathyroidism is observed in 17% to 50% of patients at 1 year after renal transplantation. In 10% of these patients, hypercalcemia is also present. This condition increases the risk of vascular calcification, correlating with inferior graft function among patients with interstitial calcification in the renal allograft. Hypertension is appears in 60% to 90% of patients after transplantation, favoring progressive graft dysfunction. Hypercalcemia per se causes hypertension. Parathyroid hormone can potentiate the pressor effects of hypercalcemia. Fourteen renal transplant recipients were included based upon: total serum calcium > 10.0 mg/dL, intact parathyroid hormone levels > 70 pg/mL, graft function > 6 months, creatinine clearance > 50 mL/min, and stable immunosuppressive therapy. We also examined blood pressure and antihypertensive treatment. Initially patients received 30 mg of cinacalcet once a day. The follow-up was up to 6 months. The mean cinacalcet dose was 40 mg/24 h. Five patients received 60 mg/24 h. Both serum calcium and iPTH decreased significantly from 10.6 (DE 0.4) to 9.8 (DE Both serum calcium and iPTH decreased significantly from 10.6 (DE 0.4)to 9.8 (DE 0.6) mg/dL (P < .001) and from 195.0 (DE 140.0) to 118.62 (DE 102.2; P < .0001). There were no significant changes in renal function, proteinuria, or tacrolimus levels. Mean blood pressure diminished from 94.1 (DE 12.0) to 88.0 (DE 7.5) mm Hg (P < .019) with no changes in antihypertensive treatment. Cinacalcet was suspended in one patient because of gastrointestinal discomfort and in another one because the iPTH was reduced to 51 pg/mL. Cinacalcet is an effective treatment for persistent hyperparathyroidism associated with hypercalcemia among renal transplant patients and may be helpful for hypertension control.
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PMID:Treatment of persistent hyperparathyroidism in renal transplant patients with cinacalcet improves control of blood pressure. 1971 27

Parathyroid hormone- (PTH-) related protein (PTHrP) and its receptor, the PTH1 receptor (PTH1R), are widely expressed in the kidney, where PTHrP exerts a modulatory action on renal function. PTHrP is known to be upregulated in several experimental nephropathies such as acute renal failure (ARF), obstructive nephropathy (ON) as well as diabetic nephropathy (DN). In this paper, we will discuss the functional consequences of chronic PTHrP overexpression in the damaged kidney using a transgenic mouse strain overexpressing PTHrP in the renal proximal tubule. In both ARF and ON, PTHrP displays proinflammatory and profibrogenic actions including the induction of epithelia to mesenquima transition. Moreover, PTHrP participates in the mechanisms of renal hypertrophy as well as proteinuria in experimental DN. Angiotensin II (Ang II), a critical factor in the progression of renal injury, appears to be, at least in part, responsible for endogenous PTHrP upregulation in these pathophysiological settings. These findings provide novel insights into the well-known protective effects of Ang II antagonists in renal diseases, paving the way for new therapeutic approaches.
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PMID:A transgenic mouse model for studying the role of the parathyroid hormone-related protein system in renal injury. 2105 97