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Turudic D, Golubic AT, Lovric M, Bilic M, Milosevic D. Age-Specific Excretion of Calcium, Oxalate, Citrate, and Glycosaminoglycans and Their Ratios in Healthy Children and Children with Urolithiasis. Biomolecules 2021; 11:biom11050758. [PMID: 34069381 PMCID: PMC8158688 DOI: 10.3390/biom11050758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/15/2021] [Accepted: 05/16/2021] [Indexed: 11/23/2022] Open
Abstract
We analyzed children with urolithiasis with age- and gender-matched healthy children. Calcium (mmol/mmol creatinine) and the calcium/citrate ratio (mol/mmol) are the only variables that differentiate children before puberty from healthy children (ROC analysis confirmed only calcium/citrate as a significant variable with cut-off value > 0.84). Peri-pubertal children are distinguished from age- and gender-matched healthy children by the following variables: citrate (mmol/mol creatinine), calcium/citrate (mol/mmol), oxalate/glycosaminoglycans (mmol/g), oxalate/citrate ratios (mmol/mmol) and oxalate/(citrate × glycosaminoglycans) (mol oxalate × mol creatinine)/(mol citrate × g glycosaminoglycans). All variables were confirmed by ROC analysis with cut-off values ≤ 327.87, >1.02, >11.24, >0.12 and >0.03, respectively. These results indicate a different risk of urinary stones development before puberty vs. pubertal/postpubertal children and increasing importance (deficiency) of citrate and glycosaminoglycans in such children. J48 classifier confirmed the importance of the oxalate/(citrate × glycosaminoglycans) and the calcium/citrate ratios (Ox/Cit × GAG 0.22 and Cit/GAG 0.612) with the practically applicable classification tree for distinguishing between pubertal/postpubertal children with urolithiasis with age- and gender-matched healthy children.
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Affiliation(s)
- Daniel Turudic
- Department of Pediatrics, University Hospital Centre Zagreb, 10000 Zagreb, Croatia
- Correspondence:
| | - Anja Tea Golubic
- Department of Nuclear Medicine and Radiation Protection, University Hospital Centre Zagreb, 10000 Zagreb, Croatia;
| | - Mila Lovric
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, 10000 Zagreb, Croatia;
| | - Marko Bilic
- Department of Urology, University Hospital “Sveti Duh”, 10000 Zagreb, Croatia;
| | - Danko Milosevic
- School of Medicine, University of Zagreb, 10000 Zagreb, Croatia;
- General Hospital Zabok and Croatian Veterans Hospital, 49210 Zabok, Croatia
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Valavi E, Nickavar A, Aeene A. Urinary metabolic abnormalities in children with idiopathic hematuria. J Pediatr Urol 2019; 15:165.e1-165.e4. [PMID: 30528095 DOI: 10.1016/j.jpurol.2018.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/28/2018] [Accepted: 11/05/2018] [Indexed: 10/27/2022]
Abstract
BACKGROUND Hematuria, either macroscopic or microscopic, is an incidental finding of multiple nephrologic or urologic disorders. Disturbances of urine inhibitors or promotors have been suggested as the potential causes of isolated idiopathic hematuria in children and its recurrence. Meanwhile, appropriate treatment of these risk factors might improve secondary asymptomatic or macroscopic hematuria. OBJECTIVES The aim of this study was to identify contribution of urinary biochemical abnormalities in children with isolated idiopathic hematuria. METHODS About 522 children with isolated hematuria were evaluated in a prospective cross-sectional study. Data such as clinical manifestations, family history, laboratory examinations, structural anomalies, and urine biochemistry were obtained. Patients with nephrolithiasis, nephrocalcinosis, tubulointerstitial disorder, genitourinary abnormality, urinary tract infection, and glomerular disorder were excluded from the study. Variables such as calcium, citrate, oxalate, phosphate, uric acid, cystine, and magnesium were measured in 24-h urine collection. In addition, serum levels of electrolytes, urea, creatinine, parathyroid hormone, and bicarbonate were identified. RESULTS Mean age at diagnosis was 5.9 years, and females outnumbered males (2/1). Of those, 88.5% had microscopic hematuria, and 12.6% experienced episodes of gross hematuria. Abdominal pain was the most common clinical manifestations. Urinary tract infection occurred in 30% of cases. Totally, 94% of patients had single or multiple metabolic abnormalities in 24-h urine excretion including hypocitraturia, 60.7%; hypomagnesuria, 58.2%; hyperuricosuria, 35.8%; hypercalciuria, 33.7%; hyperoxaluria, 33.7%; and cystinuria, 0.76%, respectively. About 8% of cases had mixed urine metabolic disturbances. Most patients had mild hematuria (red blood cell <10/high power field (hpf)), and 18% had significant hematuria (>30/hpf), with no statistical correlation to urine metabolic abnormalities. About 80% of patients had a history of nephrolithiasis in their relatives. DISCUSSION Decreased urinary inhibitor concentration followed by increased stimulator concentration were the most common abnormalities in patients with idiopathic hematuria. Accordingly, measurement of urinary biochemical concentration is highly recommended in children with isolated hematuria. In addition, investigating the therapeutic effect of potassium citrate supplements is highly recommended in these patients to prevent future stone formation and treatment of hematuria.
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Affiliation(s)
- E Valavi
- Chronic Renal Failure Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - A Nickavar
- Department of Pediatric Nephrology, Iran University of Medical Sciences, Tehran, Iran.
| | - A Aeene
- Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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Golovanova OA, Korol’kov VV. Thermodynamics and kinetics of calcium oxalate crystallization in the presence of amino acids. CRYSTALLOGR REP+ 2017. [DOI: 10.1134/s1063774517050078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Calcium oxalate urolithiasis in children: urinary promoters/inhibitors and role of their ratios. Eur J Pediatr 2016; 175:1959-1965. [PMID: 27730307 DOI: 10.1007/s00431-016-2792-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 08/17/2016] [Accepted: 09/30/2016] [Indexed: 01/07/2023]
Abstract
UNLABELLED Diagnostic criteria for determination of inclination towards idiopathic calcium oxalate (CaOx) urolithiasis based on biochemical urine parameters are not sufficiently well defined in children. The aim of this study was to determine the risk of CaOx urolithiasis in children from concentrations of calcium, oxalate, citrate, and glycosaminoglycans in urine and their ratios, all standardized in respect to creatinine. We collected and analyzed 24-h urine samples of children with CaOx urolithiasis (n = 61) and compared with urine samples of matched control group of healthy children (n = 25). The study has showed that all stone formers have higher excretion of calcium (mmol/mmol creatinine), calcium/citrate (mol/mmol), and oxalate/(citrate × glycosaminoglycans) ratio (mol Ox × mol cr)/(mol Cit × g GAGs). ROC analysis of these variables gave criteria (>0.28, >1.07, and >0.08, respectively) for distinguishing stone formers from healthy children. Biochemical urine parameters and their ratios (calcium, calcium citrate, and oxalate/(citrate × glycosaminoglycans) enable one to discriminate idiopathic calcium oxalate stone formers from healthy children. Oxalate/(citrate × glycosaminoglycans) ratio per se can serve as an independent risk for stone formation. CONCLUSION Using biochemical urine parameters and their ratios such as calcium, calcium/citrate, and oxalate/(citrate × glycosaminoglycans) enables one to determine diagnostic criteria towards idiopathic calcium oxalate urolithiasis in children. What is known: • The role of urine calcium as a promoter in calcium oxalate urolithiasis is well established. • Seldom used calcium/citrate ratio is acknowledged as a risk factor for calcium/oxalate urolithiasis. What is new: • The values of calcium and citrate in clinically and genetically proven idiopathic calcium oxalate urolithiasis make calcium/citrate ratio useful for diagnostic purposes in such stone formers. • Rarely used calcium independent oxalate/(citrate x glycosaminoglycans) ratio serves as the second best high specificity marker for idiopathic calcium oxalate urolithiasis.
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Xiao X, Dong Z, Ye X, Yan Y, Chen X, Pan Q, Xie Y, Xie J, Wang Q, Yuan Q. Association between OPN genetic variations and nephrolithiasis risk. Biomed Rep 2016; 5:321-326. [PMID: 27602211 PMCID: PMC4998211 DOI: 10.3892/br.2016.724] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 07/18/2016] [Indexed: 11/06/2022] Open
Abstract
Osteopontin (OPN) has an important role in urolithiasis. However, few studies have explored the association between OPN genetic variants and urolithiasis risk. In the present study, three single-nucleotide polymorphisms (SNPs) (rs28357094, rs11439060 and rs11730582) located on the promoter of OPN were genotyped in a total of 480 individuals, including 230 nephrolithiasis patients and 250 matched healthy controls, and the associations between these SNPs and nephrolithiasis risk in different genetic models was assessed. No significant differences were identified in the genotype and allele frequencies of OPN rs28357094 or rs11730582 (P=0.805 for rs28357094; P=0.577 for rs11730582, respectively). However, carriers with the OPN rs11439060 insertion (ins) types (ins/deletion and ins/ins) were overrepresented in urolithiasis patients compared with the controls [odds ratio (OR), 1.55; 95% confidence interval (CI), 1.08-2.22]. In the stratified analysis, the increased risk was more evident among younger subjects (adjusted OR, 1.68; 95% CI, 1.01-2.81), females (2.15; 1.14-4.08), overweight subjects (1.80; 1.07-3.05), normotensive subjects (2.48; 1.02-6.00), abnormal blood sugar subjects (1.58; 1.08-2.30), smokers (1.63; 1.02-2.60), and ever-drinkers (1.98; 1.10-3.60).. These findings revealed that the OPN rs11439060 polymorphism may act as genetic biomarker for the detection of high-risk nephrolithiasis patients.
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Affiliation(s)
- Xu Xiao
- Department of Urology, Huaiyin Hospital of Huai'an City, Huai'an, Jiangsu 223300, P.R. China
| | - Zhenjia Dong
- Department of Urology, Huaiyin Hospital of Huai'an City, Huai'an, Jiangsu 223300, P.R. China
| | - Xianqing Ye
- Department of Medicine, The Fourth Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Yao Yan
- Department of Urology, Huaiyin Hospital of Huai'an City, Huai'an, Jiangsu 223300, P.R. China
| | - Xuehua Chen
- Department of Urology, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing, Jiangsu 210029, P.R. China
| | - Qin Pan
- Department of Urology, Huaiyin Hospital of Huai'an City, Huai'an, Jiangsu 223300, P.R. China
| | - Yongfeng Xie
- Department of Urology, Huaiyin Hospital of Huai'an City, Huai'an, Jiangsu 223300, P.R. China
| | - Jie Xie
- Department of Urology, Huaiyin Hospital of Huai'an City, Huai'an, Jiangsu 223300, P.R. China
| | - Qiangdong Wang
- Department of Urology, Huaiyin Hospital of Huai'an City, Huai'an, Jiangsu 223300, P.R. China
| | - Qinbo Yuan
- Department of Urology, Huaiyin Hospital of Huai'an City, Huai'an, Jiangsu 223300, P.R. China
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Golovanova OA, Punin YO, Izatulina AR, Korol’kov VV. Crystallization of calcium oxalate monohydrate in the presence of amino acids: Features and regularities. J STRUCT CHEM+ 2015. [DOI: 10.1134/s0022476614070166] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Laube N, Berg W, Bernsmann F, Gravius S, Klein F, Latz S, Mallek DV, Porowski T, Randau T, Wasilewska A, Fisang C. Induced urinary crystal formation as an analytical strategy for the prediction and monitoring of urolithiasis and other metabolism-related disorders. EPMA J 2014; 5:13. [PMID: 25206937 PMCID: PMC4150547 DOI: 10.1186/1878-5085-5-13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 08/11/2014] [Indexed: 11/25/2022]
Abstract
Crystal formation reflects the entire composition of the surrounding solution. In case of urolithiasis, induced crystal formation in native urine has led to the development of the Bonn-Risk-Index (BRI), a valuable tool to quantify an individual's risk of calcium oxalate urolithiasis. If the progression of a disease is associated with characteristic changes in the activities of urinary components, this leads to an altered urinary crystallisation capacity. Therefore, the results of induced urinary crystal formation can be used to detect and monitor any disease linked to the altered urinary composition. Since crystal formation inherently takes into account the entire urinary composition, the influence of the disease on individual urinary parameters does not have to be known in order to monitor the consequent pathologic alterations. In this paper, we review the background of urinary crystal formation analysis and describe its established application in urolithiasis monitoring as well as potential further fields of clinical application.
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Affiliation(s)
- Norbert Laube
- Deutsches Harnsteinzentrum, Urologisches Zentrum Bonn Friedensplatz, Friedensplatz 16, Bonn 53111, Germany ; NTTF Coatings GmbH, Maarweg 32, Rheinbreitbach 53619, Germany
| | - Wolfgang Berg
- Clinic and Policlinic of Urology, Friedrich Schiller University of Jena, Lessingstraße 1, Jena 07743, Germany
| | - Falk Bernsmann
- NTTF Coatings GmbH, Maarweg 32, Rheinbreitbach 53619, Germany
| | - Sascha Gravius
- Clinic for Orthopaedics and Trauma Surgery, Friedrich-Wilhelms-Universität Bonn, Sigmund-Freud-Straße 25, Bonn 53127, Germany
| | - Florian Klein
- FH Aachen, Campus Jülich, FB Medizintechnik und Technomathematik, Heinrich-Mußmann-Straße 1, Jülich 52428, Germany
| | - Stefan Latz
- Clinic and Policlinic of Urology and Pediatric Urology, Friedrich-Wilhelms-Universität Bonn, Sigmund-Freud-Straße 25, Bonn 53127, Germany
| | - Dirk von Mallek
- Department of Research, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, Bonn, 53175, Germany
| | - Tadeusz Porowski
- Department of Pediatrics and Nephrology, Medical University of Białystok ul, Waszyngtona 17, Białystok 15-546, Poland
| | - Thomas Randau
- Clinic for Orthopaedics and Trauma Surgery, Friedrich-Wilhelms-Universität Bonn, Sigmund-Freud-Straße 25, Bonn 53127, Germany
| | - Anna Wasilewska
- Department of Pediatrics and Nephrology, Medical University of Białystok ul, Waszyngtona 17, Białystok 15-546, Poland
| | - Christian Fisang
- Clinic and Policlinic of Urology and Pediatric Urology, Friedrich-Wilhelms-Universität Bonn, Sigmund-Freud-Straße 25, Bonn 53127, Germany
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Demographic characteristics and metabolic risk factors in Croatian children with urolithiasis. Eur J Pediatr 2014; 173:353-9. [PMID: 24096520 DOI: 10.1007/s00431-013-2165-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 08/27/2013] [Accepted: 09/22/2013] [Indexed: 12/11/2022]
Abstract
The aim of this study was to assess demographic data, clinical presentation, metabolic features, and treatment in 76 children with urolithiasis presented from 2002 to 2011. Urolithiasis is responsible for 2.5/1,000 pediatric hospitalizations, with new cases diagnosed in 1.1/1,000 admissions. From the observed period, two-fold rise of incidence rate was observed. Compiling the data from other pediatric institutions in our country, we estimated present overall incidence rate in Croatia as 6.5/100,000 children under 18 years. There were 41 boys and 35 girls (ratio 1.17:1). The mean age at diagnosis was 9.7 (range 0.8-16) years and follow-up duration was 5.3 (range 1.8-10) years. Renal colic (75.0 %) and hematuria (57.89 %) were the main symptoms. In 65.78 % of children, stones were unilateral. Stones were located in kidney in 52.63 %, in the ureter in 26.32 %, and in bladder in 6.58 % cases. Stone analysis showed calcium oxalate in 75.0 % of the cases. Associated urinary tract abnormalities were found in 19.73 % children. Most common metabolic disturbances were hypercalciuria (47.37 %) and idiopathic or mild hyperoxaluria (18.42 %). Urine saturation (EQUIL2) was elevated in 61.84 % cases. Spontaneous stone evacuation occurred in 51.21 % children. Extracorporeal shock wave lithotripsy, surgical evacuation, and endoscopic removal of calculi were performed in 21.0, 6.58, and 5.26 % of cases, respectively. Follow-up conservative therapy, consisting of fluid/diet recommendations and additional potassium citrate and/or chlorothiazide in children with increased risk, was sufficient for stone recurrence prevention in 92.1 % of children. In conclusion, the study gave insight in epidemiology and metabolic disturbances of urinary stone disease in Croatian children.
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MacDougall L, Taheri S, Crofton P. Biochemical risk factors for stone formation in a Scottish paediatric hospital population. Ann Clin Biochem 2010; 47:125-30. [DOI: 10.1258/acb.2009.009146] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Background Renal stones in children, although rare, may be associated with morbidity and renal damage. Scottish children have a different ethnic composition and diet compared with paediatric populations previously studied. Urinary stone promoters include calcium, oxalate and urate. Postulated inhibitors include citrate and glycosaminoglycans (GAGs). We tested the hypothesis that Scottish paediatric stone-formers have higher excretion of urinary stone promoters (calcium/oxalate/urate) and/or lower excretion of stone inhibitors (citrate/GAGs) than children with isolated haematuria and controls. Methods In this case-controlled study, we measured creatinine, calcium, oxalate, urate, citrate and GAGs in random urine samples from 24 stone-formers (excluding inherited metabolic disorders), median age 10.2 (range 1.0–17.2) y; 25 patients with isolated haematuria, 6.3 (0.6–13.7) y; and 32 controls, 7.5 (0.8–14.7) y. Results Excretion of urinary promoters and inhibitors differed among stone-formers, haematuria and control groups for (median (range)): calcium (0.82 (0.02–2.19), 0.43 (0.08–2.65), 0.31 (0.04–2.12) mmol/mmol creatinine, respectively, P = 0.005), citrate (0.42 (0.13–0.72), 0.33 (0.05–0.84), 0.61 (0.11–1.75) mmol/mmol creatinine, P = 0.001), calcium:citrate ratio (1.68 (0.19–4.81), 1.30 (0.19–9.57), 0.54 (0.10–2.27) mmol/mmol, P < 0.0001) and the promoter:inhibitor ratio (calcium × oxalate)/(citrate × GAGs) (8.3 (1.0–82.5), 4.3 (1.2–69.5), 2.8 (0.3–13.2) mmol/g, P < 0.0001). Conclusions Scottish paediatric stone-formers had lower urinary citrate excretion and higher urinary calcium excretion, calcium:citrate ratio and promoter:inhibitor ratio compared with controls. Urinary calcium excretion and promoter:inhibitor ratio was also higher than children with isolated haematuria. Nevertheless, marked overlap between the stone-former and haematuria groups for promoter:inhibitor and calcium:citrate ratios suggests that some patients with isolated haematuria may be at future risk of urolithiasis.
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Affiliation(s)
| | - Sepideh Taheri
- Department of Medical Paediatrics, Royal Hospital for Sick Children, Edinburgh, Scotland, UK
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Liu CC, Huang SP, Tsai LY, Wu WJ, Juo SHH, Chou YH, Huang CH, Wu MT. The impact of osteopontin promoter polymorphisms on the risk of calcium urolithiasis. Clin Chim Acta 2010; 411:739-43. [PMID: 20144595 DOI: 10.1016/j.cca.2010.02.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2009] [Revised: 02/02/2010] [Accepted: 02/03/2010] [Indexed: 11/27/2022]
Abstract
BACKGROUND Osteopontin (OPN) is an important modulator of urolithiasis formation. Three functional polymorphisms (-66T/G, -156delG/G, and -443T/G) on the promoter region of the OPN gene have been found to affect the gene expression and transcriptional activity. This study investigated the association of those three functional polymorphisms with the risk of calcium urolithiasis. METHODS A total of 249 cases diagnosed with calcium urolithiasis and 247 age- and sex-matched healthy controls were recruited from Kaohsiung Medical University Hospital between June, 2003 and February, 2007. All subjects completed a detailed questionnaire survey, and provided blood and urine samples for biochemical evaluations. Three single nucleotide polymorphisms were determined by using TaqMan 5' allelic discrimination assay. RESULTS In-156delG/G polymorphism, subjects who carried delG allele had a significantly higher risk of developing calcium urolithiasis than those with G allele (odds ratio=1.39; 95% confidence interval=1.02-1.90; P=0.037). In stone cases, subjects with delG/G and delG/delG genotypes also had significantly higher urinary ratio of calcium to OPN than those with G/G genotype (11.8+/-15.9 vs 7.08+/-5.26, P=0.021). CONCLUSIONS The -156 delG/G polymorphism of OPN gene could serve as a candidate genetic marker used to evaluate the risk of calcium urolithiasis.
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Affiliation(s)
- Chia-Chu Liu
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
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Abstract
PURPOSE OF REVIEW The management of urolithiasis is a clinical challenge worldwide which may result in difficulty in diagnosis, treatment and prevention of recurrence. Artificial neural networks (ANNs) are well described adjuncts to many aspects of clinical urological practice. We review literature published in on-line Medline-citable English language journals to assess whether ANNs are useful in clinician-led decision-making processes in urolithiasis. RECENT FINDINGS Studies have examined the role of ANNs in prediction of stone presence and composition, spontaneous passage, clearance and regrowth after treatment. These reports suggest that ANNs can identify important predictive variables and accurately predict treatment outcome. SUMMARY Although well described in general urological practice, there is comparatively little research into the role of ANNs in urolithiasis. Initial results appear promising; however, further prospective studies are necessary to determine if this mode of analysis is superior to standard statistical predictive methods.
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Affiliation(s)
- Prabhakar Rajan
- Department of Urology, The Scottish Lithotriptor Centre, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, Scotland, UK
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Abstract
BACKGROUND Both urinary and biliary stones can contain calcium. Bile salts (BA), which are known to bind Ca2+, are commonly used to dissolve the latter but not the former. METHODS The effect of physiologic BA on calcium oxalate (CaOx) precipitation was evaluated by a recently developed method. RESULTS The Ca2+ binding properties of BA were confirmed by small but significant decreases in pH observed following addition of CaCl2 to bile acids solutions. More importantly, BA inhibited CaOx precipitation with effective concentrations of approximately 10-3 mol/L. The clinical relevance of the latter observation is presently unknown but it is of note that in the same in vitro assay, the activity of BA appeared comparable to that of citric acid, the most common drug for urolithiasis. Although BA do not reach mmol/L levels in urine, they are known to change the physicochemical properties of this fluid, possibly slowing down the crystal growth process. However, the hypothetical therapeutic use of BA in former stone patients would present at least two major problems: (i) hepatotoxicity and (ii) lithogenic activity, due to hyperoxaluria subsequent to increased intestinal absorption of oxalate. CONCLUSION The ability of BA in effectively binding calcium ions and in inhibiting the precipitation of CaOx appears of interest from both a physiopathologic and a pharmacologic point of view, even if it does not currently seem exploitable for prophylactic or therapeutic purposes.
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Affiliation(s)
- L Saso
- Department of Pharmacology of Natural Substances and General Physiology, University of Rome, Rome, Italy.
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