Reversible fluorescence modulation of BSA stabilised copper nanoclusters for the selective detection of protamine and heparin.

Protamine and heparin are the most important polyionic drugs used during surgeries and extracorporeal therapies. In this article, a selective and sensitive fluorescence method for the detection of both protamine and heparin was developed by using bovine serum albumin stabilised copper nanoclusters. Blue emitting fluorescent copper nanoclusters were synthesized in aqueous solution using bovine serum albumin as a capping agent and a reducing agent. A one pot microwave assisted method was adopted to synthesize fluorescent copper nanoclusters showing emission at 410 nm upon excitation at 330 nm. The fluorescence of copper nanoclusters was found to be enhanced after the addition of protamine and the limit of detection obtained is 0.12 ng mL-1. The significant enhancement in fluorescence can be attributed to the electrostatic interactions between the copper nanocluster and protamine. In contrast, the enhanced fluorescence intensity of the copper nanocluster with protamine added was decreased after the addition of heparin, and the copper nanocluster regained its original fluorescence intensity. This can be attributed to the strong interaction of protamine with heparin and the limit of detection was calculated as 0.0406 ng mL-1. The selectivity and sensitivity of the sensor for both protamine and heparin were also determined in the presence of potentially co-existing biomolecules, cations, and anions and satisfactory results were obtained. Additionally the validity of the proposed protamine and heparin sensor was attested in real sample matrices such as human urine samples and human blood serum samples. The results exhibited that the recovery percentage of protamine and heparin reached 98-99% and 92-99% in urine samples and 97-99% in serum samples.

Repeated Oral or Subcutaneous LMWH Has similar Antithrombotic Activity in a Rat Venous Thrombosis Model: Antithrombotic Activity Correlates With Heparin on Endothelium When Orally Administered.

Low-molecular-weight heparins (LMWHs) endure as important drugs for thromboprophylaxis. Although clinical use relies on the subcutaneous (SC) route, our previous studies show that single-dose orally administered LMWHs have antithrombotic activity. Since thromboprophylaxis requires long-term treatment, we examined antithrombotic effects of subacute oral LMWHs in a rat venous thrombosis model and compared results to SC or single-dose oral administration. We measured LMWH in endothelium and plasma, weight change and complete blood counts (CBC). Oral LMWH tinzaparin (3 × 0.1 mg/kg/12 or 24 hours) or reviparin (3 × 0.025 mg/kg/24 hours) significantly decreased thrombosis compared to saline. In the subacute study (60 × 0.1 mg/kg/12 hours), oral or SC tinzaparin significantly reduced thrombosis compared to saline but not to single or 3 × 0.1 mg/kg/12 hours oral tinzaparin. Antithrombotic effects were similar between oral and SC administration. LMWH was found on endothelium following oral but not SC administration. Endothelial concentrations were significantly correlated with incidence of stable thrombi ( P = 0.021 and 0.04 for aortic and vena cava endothelium respectively, χ2 test) and total thrombi ( P = 0.003 for vena cava endothelium). Anti-Xa activity was significantly greater for oral or SC LMWH than saline and significantly greater for SC versus oral LMWH. Values for CBCs were within normal ranges (mean ± 2 SD). There was no evidence of bleeding. Weight gain was similar between groups. In conclusion, subacute oral and SC LMWH have similar antithrombotic effects. Antithrombotic activity with oral administration is correlated with endothelial LMWH concentrations but not with plasma anticoagulant activity.

Plasma and urinary glycosaminoglycans in the course of juvenile idiopathic arthritis.

OBJECTIVES: The aim of the study was to perform analyses of plasma and urinary glycosaminoglycan isolated from juvenile idiopathic arthritis (JIA). METHODS, RESULTS: Chondroitin/dermatan sulfate (CS/DS), heparan sulfate/heparin (HS/H) and hyaluronic acid (HA) were evaluated in samples obtained from JIA patients before and after treatment. Electrophoretic analysis of GAGs identified the presence of CS, DS and HS/H in plasma of healthy subjects and JIA patients. CS were the predominant plasma GAGs constituent in all investigated subject. The plasma CS level in untreated patients was significantly decreased. Therapy resulted in an increase in this glycan level. However, plasma CS concentration still remained higher than in controls. Increased levels of DS and HA in untreated JIA patients were recorded. Anti-inflammatory treatment led to normalization of these parameters concentrations. Plasma and urinary concentrations of HS/H were similar in all groups of individuals. Urinary CS/DS and HA were decreased only in untreated patients. CONCLUSIONS: The data presented indicate that changes in plasma and urinary glycosaminoglycan occur in the course of JIA. There are probably the expression of both local articular cartilage matrix and systemic changes in connective tissue remodeling.

Inhibition of urinary macromolecule heparin on aggregation of nano-COM and nano-COD crystals.

PURPOSE: This research aims to study the influences of heparin (HP) on the aggregation of nano calcium oxalate monohydrate (COM) and nano calcium oxalate dihydrate (COD) with mean diameter of about 50 nm. METHOD: The influences of different concentrations of HP on the mean diameter and Zeta potential of nano COM and nano COD were investigated using a nanoparticle size Zeta potential analyzer. RESULTS: HP could be adsorbed on the surface of nano COM and nano COD crystals, leading to an increase in the absolute value of Zeta potential on the crystals and an increase in the electrostatic repulsion force between crystals. Consequently, the aggregation of the crystals is reduced and the stability of the system is improved. The strong adsorption ability of HP was closely related to the -OSO3- and -COO- groups contained in the HP molecules. X-ray photoelectron spectroscopy confirmed the coordination of HP with Ca2+ ions of COM and COD crystals. CONCLUSION: HP could inhibit the aggregation of nano COM and nano COD crystals and increase their stability in aqueous solution, which is conducive in inhibiting the formation of calcium oxalate stones.

Effect of oral administration of unfractionated heparin (UFH) on coagulation parameters in plasma and levels of urine and fecal heparin in dogs.

The effects of heparin administration, by the oral route, were evaluated in dogs. In single and multiple dose studies (single 7.5 mg/kg, multiple 3 × 7.5 mg/kg per 48 h), plasma, urine, and fecal samples were collected at various times up to 120 h after oral administration of unfractionated heparin. Changes in plasma and urine anti-Xa activity, plasma and urine anti-IIa activity, plasma activated partial thromboplastin time (APTT) and antithrombin (ATIII), and chemical heparin in urine and feces were examined with time. There was support for heparin absorption, with significant differences in APTT, heparin in plasma as determined by anti-Xa activity (Heptest) in the single dose study and plasma anti-Xa activity, anti-IIa activity and ATIII; and chemical heparin in urine in the multiple dose study. No clinical evidence of bleeding was detected in any dog during the studies. Oral heparin therapy may be applicable for thromboembolic disease in animals. Further studies are warranted to determine the effects of oral heparin at the endothelial level in the dog.

Les effets de l'administration d'héparine, par voie orale, furent évalués chez des chiens. Dans des études suite à une administration unique et à des administrations multiples (unique 7,5 mg/kg; multiples 3 × 7,5 mg/kg par 48 h), des échantillons de plasma, d'urine et de fèces furent prélevés à différents intervalles jusqu'à 120 h suivant l'administration orale d'héparine non-fractionnée. On examina dans le temps les changements de l'activité anti-Xa dans le plasma et l'urine, l'activité anti-IIa dans le plasma et dans l'urine, le temps de thromboplastine partielle (APTT) et d'antithrombine (ATIII) activé par le plasma, et l'héparine dans l'urine et les fèces. Il y a évidence d'absorption d'héparine, avec des différences significatives de l'APTT, de l'héparine plasmatique tel que déterminé par l'activité anti-Xa (Heptest) dans l'étude à dose unique et dans l'activité anti-Xa plasmatique, l'activité anti-IIa et l'ATIII; et de l'héparine chimique dans l'urine lors de l'étude à doses multiples. Aucune évidence clinique de saignement ne fut détectée chez les chiens au courant des études. Une thérapie orale à l'héparine pourrait être applicable pour des maladies thromboemboliques chez les animaux. Des études supplémentaires sont nécessaires afin de déterminer les effets d'administration d'héparine orale au niveau endothélial chez les chiens.(Traduit par Docteur Serge Messier).

Critical parameters for the analysis of anionic oligosaccharides by desorption electrospray ionization mass spectrometry.

Sulfated oligosaccharides derived from glycosaminoglycans (GAGs) are fragile compounds, highly polar and anionic. We report here on the rare but successful application of desorption electrospray ionization (DESI) - LTQ-Orbitrap mass spectrometry (MS) to the high-resolution analysis of anionic and sulfated oligosaccharides derived from the GAGs hyaluronic acid and heparin. For that purpose, key parameters affecting DESI performance, comprising the geometric parameters of the DESI source, the probed surface and the spraying conditions, applied spray voltage, flow rates and solvent composition were investigated. Under suitable conditions, the DESI technique allows the preservation of the structural integrity of such fragile compounds. DESI enabled the sensitive detection of anionic hyaluronic acid and heparin oligosaccharides with a limit of detection (LOD) down to 5 fmol (≈10 pg) for the hyaluronic acid decasaccharide. Detection of hyaluronic acid oligosaccharides in urine sample was also successfully achieved with LOD values inferior to the ng range. Multistage tandem mass spectrometry (MS(n) ) through the combination of the DESI source with a hybrid linear ion trap-orbitrap mass spectrometer allowed the discrimination of isomeric sulfated oligosaccharides and the sequence determination of a hyaluronic acid decasaccharide. These results open promising ways in glycomic and glycobiology fields where structure-activity relationships of bioactive carbohydrates are currently questioned.

Mucopolysaccharidosis type II in females and response to enzyme replacement therapy.

Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is an X-linked lysosomal storage disease caused by a deficiency of iduronate-2-sulfatase (IDS). Two affected girls with moderate and severe forms of MPS II with normal karyotypes and increased urinary dermatan sulphate and heparin sulphate excretion and marked deficiencies of IDS activity are reported. Molecular studies showed that case 1 has a heterozygous mutation c.1568A > G (p.Y523C) associated with almost totally skewed inactivation of the normal maternal X chromosome, and case 2 has a heterozygous deletion that includes exons 1-4 of IDS (minimal deletion range c.1-103_184del). The multi-exon deletion correlated with early onset of the disease and severe phenotype with intellectual disability, whereas the missense mutation was associated with moderate developmental delay. Although genotype-phenotype correlation in MPS II is difficult, gene deletions seem to correlate with more severe clinical manifestation of the disease. Enzyme replacement therapy (ERT) in these two females resulted in disease stabilization in both.

Neonatal screening for mucopolysaccharidoses by determination of glycosaminoglycans in the eluate of urine-impregnated paper: preliminary results of an improved DMB-based procedure.

BACKGROUND: The fact that mucopolysaccharidoses (MPSes) are now treatable, and that the earlier treatment is initiated the better, is an indication for neonatal screening. The most efficient approach seems likely to be a multi-tier procedure in which screening for urinary glycosaminoglycan (GAG) is followed by enzyme determinations in heelprick blood of newborns screening positive. Hitherto the method of choice for the determination of GAG has been the measurement of absorbance by a complex of GAG and 1,9-dimethylmethylene blue (DMB). METHOD: We evaluated a DMB method in which absorbance by DMB is measured following its addition to the eluate obtained from paper-borne newborn urine samples and is normalized relative to urinary creatinine. Calibration is performed with chondroitin-6-sulfate (Ch-6-S). RESULTS: The limits of detection and quantification of GAG were 1.98 and 5.94 mg/dl, respectively. The within-run coefficients of variation (CVs) of the GAG/creatinine ratio for 25, 31, and 70 mg/dl solutions of Ch-6-S in urine were 21.8, 16.4, and 10.5%, respectively, and the corresponding between-run CVs were 25.0, 13.5, and 10.1%. Recovery from the urine spiked with 31 mg Ch-6-S/dl was 94.8%. Accuracy was also acceptable for all other GAGs except hyaluronic acid. For neonatal screening, the diagnostic threshold was tentatively established as 800 mg GAG/g creatinine, the 95th centile of samples from 903 infants aged 3-28 days, but the value of the GAG/creatinine ratio was negatively correlated with age. Application of the new method to samples from older individuals with and without MPS achieved 100% sensitivity and specificity when used with an age-dependent threshold taken from the literature on the original DMB method. CONCLUSION: If used in the first tier of a multi-tier screening protocol, the proposed method would allow the detection of abnormal levels of all GAGs except hyaluronic acid.

Increased plasma anti-Xa activity and recovery of heparin from urine suggest absorption of orally administered unfractionated heparin in human subjects.

Although heparin is not generally administered orally, the results of studies involving rats suggest that heparin is absorbed, with low levels in plasma but extensive distribution to the endothelium. To determine whether evidence of absorption after oral administration can also be demonstrated in human subjects, we administered unfractionated porcine heparin in a single dose of 1000 U/kg to 6 healthy human subjects. Plasma anticoagulant activity was monitored between 5 minutes and 72 hours after administration, and chemical heparin concentrations were determined in 24-hour urine samples for as long as 120 hours after administration. Plasma anticoagulant activity, determined by anti-Xa activity, increased as soon as 5 minutes after heparin administration, peaked at 120 minutes, and was still increased 72 hours after administration. Values were significantly greater 15 minutes to 48 hours after administration compared with values before administration (paired t test). Mean activated partial thromboplastin time and Heptest values in subjects given heparin were greater than those in controls 15 and 30 minutes and 5 to 120 minutes after administration, respectively. Heparin was recovered from urine as long as 120 hours after administration (the latest time point at which samples were collected); greater amounts were excreted between 48 and 120 hours than before 48 hours. Recovery from both plasma and urine suggest that unfractionated heparin administered orally is absorbed in human subjects, is widely distributed, and is found in the body at least 120 hours after administration. Because heparin is readily bound to endothelium, recovery from plasma and urine likely reflect considerable amounts with endothelium, as has been observed in other species.

Bladder stretch alters urinary heparin-binding epidermal growth factor and antiproliferative factor in patients with interstitial cystitis.

PURPOSE: The etiology of interstitial cystitis is unknown. Urine from patients with interstitial cystitis has been shown to inhibit urothelial proliferation through a putative antiproliferative factor and to contain decreased levels of heparin-binding epidermal growth factor-like growth factor (HB-EGF) compared to controls. Stretch of detrusor smooth muscle cells is known to stimulate HB-EGF production. Because bladder hydrodistention sometimes alleviates the symptoms of interstitial cystitis, we determined whether the stretch stimulus of hydrodistention alters antiproliferative factor activity and/or HB-EGF in interstitial cystitis urine specimens. MATERIALS AND METHODS: Urine was collected immediately before, and 2 to 4 hours and 2 weeks after hydrodistention from 15 patients with symptoms and cystoscopic findings compatible with interstitial cystitis and 13 controls. Hydrodistention was performed with the subject under general or regional anesthesia and bladders were distended to 80 cm. water 3 times. Urinary HB-EGF was measured by enzyme-linked immunosorbent assay and urinary antiproliferative factor activity was determined by measuring 3H-thymidine uptake by normal human bladder urothelial cells. RESULTS: Hydrodistention significantly increased urinary HB-EGF in patients with interstitial cystitis toward normal control values (before distention p = 0.003, 2 weeks after distention p = 0.67). Urine antiproliferative factor activity decreased significantly after hydrodistention in patients with interstitial cystitis. However, antiproliferative factor activity in interstitial cystitis and control specimens was still statistically different 2 weeks after distention (before distention p = 0.0000004, 2 weeks after distention p = 0.04). CONCLUSIONS: Bladder stretch increased HB-EGF and conversely reduced antiproliferative factor activity in urine from patients with interstitial cystitis but not controls up to 2 weeks after distention. These results provide additional evidence for the possible role of antiproliferative factor and decreased HB-EGF in the pathophysiology of interstitial cystitis. To our knowledge this is also the first human study to show that in vivo bladder stretch can alter urinary factors that regulate cell growth.

HPLC determination of ITF 188 and its metabolite ITF 1078 in urine after intranasal administration of new heparin salt ITF 1300 to dogs.

Heparin salt ITF 1300 in which low molecular weight heparin is salified with a new counterion, di-[3-(N,N-dibutylamino)]propyl carbonate (ITF 188), was selected for the pharmacological development. A specific, sensitive and reproducible HPLC method for the determination of ITF 188 and its alcoholic metabolite ITF 1078 in urine was developed. The method was employed for the study of urinary excretion of the counterion after intranasal administration of ITF 1300 to dogs. The total amount of ITF 188 and ITF 1078 found in urine within 72 hours after the nasal instillation of ITF 1300 accounts for about 5% of the administered dose.

Urinary chondroitin sulfates, heparan sulfate and total sulfated glycosaminoglycans in interstitial cystitis.

PURPOSE: We compared urinary glycosaminoglycan levels in patients with interstitial cystitis and healthy controls. MATERIALS AND METHODS: Total sulfated glycosaminoglycans assayed by dimethylmethylene blue binding and individual glycosaminoglycans analyzed by cellulose acetate electrophoresis were compared in patients with interstitial cystitis and healthy controls. Also, multiple urine samples were obtained from healthy female controls for 2 months to assess the relationship of urinary glycosaminoglycan and creatinine concentrations, and to determine whether glycosaminoglycan excretion changes during the menstrual cycle. RESULTS: Total sulfated glycosaminoglycan and creatinine concentrations correlated well in random voided samples. Menstrual cycle day did not affect total sulfated glycosaminoglycan levels. Cellulose acetate electrophoresis revealed 3 bands corresponding to chondroitin sulfates, heparan sulfate and acidic glycoprotein. Patients with interstitial cystitis had decreased urinary concentrations of each of these individual components and total sulfated glycosaminoglycans. However, glycosaminoglycan-to-creatinine ratios were similar in interstitial cystitis and control urine. CONCLUSIONS: Using these assays total and individual urinary glycosaminoglycan levels normalized to creatinine were not altered in interstitial cystitis.

Disposition of a new heparan sulfate with fibrinolytic activity in the rat.

A fluoresceinated derivative of a new heparan sulfate fraction (HS) was administered by intravenous route to rats. The compound was similar to the unlabelled compound and biologically active. After i.v. injection, pharmacokinetic parameters were analyzed and discussed according to a two-compartment open model. In addition, experiments performed with the unlabelled compound indicate that the HS is absorbed through the intestinal mucosa, reaches the highest plasmatic concentration after 90 min and is partially recovered, unmodified, in urine. Other sets of experiments, in vitro, show that the compound is degraded in the presence of hepatic microsomal preparation while it is not metabolized by plasma, confirming that the liver plays an important role in the metabolism and consequently on the activity of the compound. The overall results are in accordance with the fibrinolytic and antithrombotic activity of HS administered orally to animals and man.

Pharmacokinetics and biodistribution of technetium 99m labelled standard heparin and a low molecular weight heparin (enoxaparin) after intravenous injection in normal volunteers.

For a better understanding of low molecular weight heparin pharmacokinetics, 99m technetium labelled heparin and enoxaparin were injected intravenously to four normal volunteers, after approval by the Ethics Committee and preliminary animals studies. In vitro and in vivo, the labelled products proved to be stable and identical to the non-labelled drugs. Radioactivity curves in blood, organs and urines were similar for both products. Anti Xa plasma half-life was 3 times longer for enoxaparin than for heparin. Anti IIa plasma half-lives were similar. However, radioactivity persisted much longer than biological activities for both products. After chromatography, most of the radioactivity was bound to AT III, where an anti Xa activity peak was also detected. The anti Xa activity peak seen after adding AT III to plasma was much higher with heparin than with enoxaparin. In urine, biological activities, measured with AT III supplementation, were higher with enoxaparin than with heparin. These results suggest that phenomena other than biodistribution are responsible for the differences in pharmacokinetics observed between these two products. The two most likely explanations are differences in metabolism and/or a release of an endogenous factor.

Prevention of albuminuria by captopril in diabetic rats.

1. Streptozotocin diabetic rats were treated with captopril (50 mg l), an angiotensin converting enzyme-inhibitor, in drinking water for 20 weeks. 2. Systolic blood pressure and 24-hr urinary excretions of heparan sulfate and albumin were done at 2, 8, 16 and 20 weeks. 3. At the end of 20 weeks, all rats were killed, kidneys removed and glomeruli isolated. 4. Total glycosaminoglycan and heparan sulfate synthesis were determined by incubating glomeruli in the presence of 35S-sulfate. 5. Captopril significantly lowered blood pressure in diabetic rats 8 weeks after treatment. 6. Diabetic glomeruli synthesized less total glycosaminoglycan and heparan sulfate than glomeruli from nondiabetic rats. 7. Further characterization of heparan sulfate by ion-exchange chromatography showed that the fraction eluted with 1 M NaCl was significantly lower and the fraction eluted with 1.25 M NaCl significantly higher in diabetic than in normal rats. 8. Therapy with captopril normalized not only glomerular synthesis and content but also various fractions of heparan sulfate in diabetic rats. 9. Excretions of heparan sulfate and albumin were significantly higher in diabetic than in nondiabetic rats. 10. Captopril therapy did significantly lower but not normalize both these excretions in diabetic rats. 11. The data suggest that catopril therapy improves albuminuria through preservation of glomerular heparan sulfate and prevention of its urinary loss in diabetic rats.

Increased levels of fibroblast growth factor-like activity in urine from patients with bladder or kidney cancer.

Growth factor activity was partially purified from human renal tumors and a human bladder cancer cell line by heparin-Sepharose chromatography. This activity stimulated bovine capillary endothelial cell proliferation and DNA synthesis in BALB/c 3T3 cells. Partially purified growth factor preparations from these tumors contained a protein with an approximate molecular weight of 17,000 which was recognized by a polyclonal antiserum raised against a peptide fragment of basic fibroblast growth factor (FGF). This growth factor activity appears to be related to basic fibroblast growth factor. Measurement of FGF-like activity in 50 urine samples from 32 adult males showed that 55% (6 of 11) of the urine samples from patients with bladder cancer and 100% (7 of 7) of the urine samples from patients with kidney cancer contained activity equivalent to more than 20 ng of basic FGF/h of urine production. In contrast, only 6% (2 of 32) of the urine samples from controls, patients with a benign disease, or patients with a history of bladder or kidney cancer contained this level of growth factor activity. These results suggest that patients with bladder or kidney cancer release an FGF-like factor into urine which may be used as a marker for these tumors.

Absorption of heparin, LMW heparin and SP54 after subcutaneous injection, assessed by competitive binding assay.

Unfractionated heparin, pentosan polysulphate (SP54) and the low molecular weight heparins CY216 and CY222 were injected subcutaneously at a minimum of weekly intervals into 5 healthy volunteers. The dose was 75 mg in all cases. Concentrations of administered glycosaminoglycan in serial plasma samples and voidings of urine were measured using a competitive binding assay, and biological activity was assessed in plasma using APTT and anti-Xa clotting assays. There was wide individual variation in the absorption of unfractionated heparin as indicated both by the maximal plasma concentrations reached 2-3 h after injection and by the area under the concentration vs. time curve. The efficiency of absorption increased and the individual variation decreased with decreasing molecular weight of the administered glycosaminoglycan. Urinary excretion correlated with plasma concentration, and recovery in the urine also increased with decreasing molecular weight. Similar patterns of uptake and clearance were indicated by the APTT and competitive binding assays, but anti-Xa clotting activity could be detected in the plasma after clearance of the administered glycosaminoglycan.

Un nuevo método químico específico para la determinación de la heparina y otros glicosaminoglicanos naturales / New chemical method for determination of heparin and other glycosaminoglycans

El objetivo de la investigación fue la obtención de un método que permitiera la determinación de la heparina y otros glicosaminoglicanos (GAG) naturales en las cantidades pequeñas en que se los encuentra en los líquidos biológicos. El método debía ser sencillo y de la mayor especificidad posible. Se ha logrado poner a punto la reacción de los hidratos de carbono con el indol en medio ácido, de manera tal que, dependiendo de las condiciones de una hidrólisis previa también en medio ácido, sea específica, bien para la heparina y el dermatán sulfato, o bien para el condroitín 4-sulfato o el condroitín 6-sulfato. La albúmina humana y las sales inorgánicas no interfieren con la reacción, lo que valoriza el método para su aplicación a material biológica. La sencillez de la técnica, pues no requiere ninguna precipitación previa, acrecienta en mayor medida su valor potencial para la Bioquímica analítica (AU)

Un nuevo método químico específico para la determinación de la heparina y otros glicosaminoglicanos naturales / New chemical method for determination of heparin and other glycosaminoglycans

El objetivo de la investigación fue la obtención de un método que permitiera la determinación de la heparina y otros glicosaminoglicanos (GAG) naturales en las cantidades pequeñas en que se los encuentra en los líquidos biológicos. El método debía ser sencillo y de la mayor especificidad posible. Se ha logrado poner a punto la reacción de los hidratos de carbono con el indol en medio ácido, de manera tal que, dependiendo de las condiciones de una hidrólisis previa también en medio ácido, sea específica, bien para la heparina y el dermatán sulfato, o bien para el condroitín 4-sulfato o el condroitín 6-sulfato. La albúmina humana y las sales inorgánicas no interfieren con la reacción, lo que valoriza el método para su aplicación a material biológica. La sencillez de la técnica, pues no requiere ninguna precipitación previa, acrecienta en mayor medida su valor potencial para la Bioquímica analítica