Drabkin's Reagent Research Articles

Naoxueshu oral liquid promotes hematoma absorption by targeting CD36 in M2 microglia via TLR4/MyD88/NF-κB signaling pathway in rats with intracerebral hemorrhage

Ethnopharmacological relevanceIntracerebral hemorrhage (ICH) is a major public health issue that leads to elevated rates of death and disability and has few proven treatments. Naoxueshu oral liquid (NXS), a TCM patent drug, is widely used in patients with ICH. Although a series of clinical studies have confirmed the efficacy and safety of NXS, the underlying mechanism of hematoma absorption is unclear. Aim of the studyOur work aimed to elucidate the effect and mechanism of NXS on hematoma absorption in rats with ICH. Materials and methodsInduction of ICH model in the rats with intracerebral injection of collagenase VII, followed by treatment with NXS and Edaravone as a control neuroprotection medication. Neural functional recovery was assessed using mNSS, foot fault test, corner test, forelimb grip-traction test, and adhesive removal test. Hematoma absorption was assessed by the spectrophotometric hemoglobin assay with Drabkin's reagent. The protein expression of CD36, M2 microglia marker (CD206 and YM-1) and TLR4/MyD88/NF-κB pathway related proteins were determined by Western blot and immunofluorescence. ResultsNXS could significantly ameliorate the ICH recovery of neural and locomotor function as well as reduce hemorrhage volume. NXS could increase the expression of CD36 expressed in M2 microglia and promote M2 microglia polarization. Simultaneously, NXS significantly suppressed protein expressions of TLR4, MyD88, and NF-κB following ICH in rats. The results indicated that lipopolysaccharide (LPS), TLR4 specific agonist, could partially reverse the change in ICH rats administrated with NXS. ConclusionsNXS promotes hematoma absorption by targeting CD36 expression in M2 microglia via TLR4/MyD88/NF-κB signaling pathway in rats with ICH. Collectively, current research provides a novel theoretical basis for the clinical application of NXS.

Inulin Modulates Iron Metabolism in Piglets Fed a High‐Iron Milk Formula

ObjectiveIron‐fortified formula provides excessive amount of iron compared to breast milk, and there is a rising concern over the adverse effects of dietary iron overexposure at infancy. The study aimed to evaluate the effect of dietary prebiotics and synbiotics supplement on iron absorption and metabolism in a milk‐fed neonatal piglet model.MethodsOn postnatal day (PD) 2, piglets (n = 6/treatment) were blocked by sex and body weight (BW) and randomized to the following dietary treatments: 1) an iron‐adequate milk formula with 60 mg Fe/kg milk solid (AI), 2) a high‐iron milk formula with 480 mg Fe/kg milk solid (HI), 3) the HI formula supplemented with inulin (Orafti®IPS, Beneo) at 6% of milk solid (HIP), 4) the HIP formula with an oral supplement of 5 ml of Lactobacilus agilis YZ050 (L. agilis) at 1x109 CFU/ml once in every 3 days (HIS). Pigs were fed at 270 mL of milk/kg BW in 14 meals daily through an automatic programmable milk delivery system. Blood and fecal samples were collected on PD 1, 7, 14, 21, 28. On PD 28, piglets were euthanized, and tissue samples were collected. Tissue and fecal samples were analyzed for iron concentrations using flame atomic absorption spectrophotometry analysis. Blood samples were analyzed for hemoglobin (Hb) using Drabkin’s reagent and hematocrit (Hct) using Unico Micro‐hematocrit centrifuge. The mRNA expression of iron transporters and regulatory proteins in the intestinal tissues were determined by RT‐qPCR. Data were analyzed for one‐ or two‐way ANOVA with repeated measure for variables measured over time. Statistical significance was declared at P ≤0.05.ResultsOverall growth performance of piglets across the groups showed no statistical significance during the study. Both Hct and Hb were higher in HI, HIP, HIS than in AI during the study (P≤ 0.05). In comparison with AI, high‐iron formula markedly increased fecal iron concentration on PD7, 14, 21, 28 (P≤ 0.05) with exception of the comparison between AI and HIP on PD7. Use of inulin in HIP reduced fecal iron on PD21 and 28 in comparison with HI (P≤ 0.05). High‐iron formula significantly increased hepatic iron compared to AI (P≤ 0.05), while use of inulin alone or in combination with probiotics attenuated hepatic iron accumulation in comparison with HI (P≤ 0.05). The same response was also observed in analysis of iron concentration in colon content. Duodenal iron concentration was higher in HIP and HIS than in AI (P≤ 0.05), whereas ileal iron concentration was higher in HI than in AI (P≤ 0.05). The mRNA expression of divalent metal transporter 1 (DMT1) in colon was lower in HIP compared to AI (P ≤ 0.05); duodenal cytochrome b (DYCTB) in colon was lower in HI and HIP compared to AI (P ≤ 0.05).ConclusionHigh‐iron formula resulted in hepatic iron overload and increased iron flux in the large intestine and feces. Use of inulin alone or in combination with L. agilis diminished iron deposition in liver, colon, and feces caused by consumption of high‐iron formula in piglets.

Anti-inflammatory and anti-angiogenesis effect of bee pollen methanolic extract using air pouch model of inflammation.

Background and purpose:Research on new drugs with a natural source and low side effects is a priority in pharmacology studies. The present study was conducted to investigate the anti-inflammatory and anti-angiogenesis effects of bee pollen extract in the air pouch model of inflammation.Experimental approach:To achieve this goal, male rats were moderately anesthetized and then 20 and 10 mL of sterile air were subcutaneously injected into the intrascapular area of the back of the rat on first and third days, respectively. On day 6, inflammation was induced by intrapouch injection of carrageenan. Normal saline in the control group and bee pollen methanolic extract (50, 100, and 200 mg/pouch) were administered at day 6, simultaneously with carrageenan, and then for 2 consecutive days only normal saline and the extracts were injected. Following sacrificing the rats the pouch was opened and the exudate volume, leukocyte accumulation, granulation tissue weight, vascular endothelial growth factor (VEGF), interleukin 1beta, and tumor necrosis factor alpha (TNF-α) concentrations were determined 3 days after induction of inflammation. In order to investigate the angiogenesis, the granulation tissue was removed, homogenized in the Drabkin’s reagent, and then centrifuged. The supernatant was filtered and the hemoglobin concentration was determined using a spectrophotometer.Results:Bee pollen extract significantly decreased the exudate volume, leukocyte accumulation, granulation tissue weight, angiogenesis, VEGF, and TNF-α concentration.Conclusion and implications:The findings of the current study revealed that bee pollen methanolic extract has an anti-inflammatory and anti-angiogenesis effect, which could be attributed to the inhibition of VEGF and TNF-α production in the inflammatory exudates.

Updated Method for In Vitro Analysis of Nanoparticle Hemolytic Properties.

Hemolysis is damage to red blood cells (RBCs), which results in the release of the iron-containing protein hemoglobin into plasma. An in vitro assay was developed and described earlier for the analysis of nanoparticle hemolytic properties. Herein, we present a revised version of the original protocol. In this protocol, analyte nanoparticles and controls are incubated in blood. Undamaged RBCs are removed by centrifugation and hemoglobin, released by the damaged erythrocytes, is converted to cyanmethemoglobin by incubation with Drabkin's reagent. The amount of cyanmethemoglobin in the supernatant is measured by spectrophotometry. This measured absorbance is compared to a standard curve to determine the concentration of hemoglobin in the supernatant. The measured hemoglobin concentration is then compared to the total hemoglobin concentration to obtain the percentage of nanoparticle-induced hemolysis. The revision includes updated details about nanoparticle sample preparation, selection of nanoparticle concentration for the in vitro study, updated details about assay controls and case studies about nanoparticle interference with the in vitro hemolysis assay.

A Rare Case of Acute Cyanide Poisoning from Cyanmethemoglobin Reagent Ingestion

Acute poisoning from cyanides frequently gives rise to lethal toxicity and rapid death. Although many cases of acute cyanide poisoning resulting from inhalation of hydrogen cyanide and ingestion of inorganic cyanide salts have been reported, acute poisoning resulting from ingestion of cyanmethemoglobin reagent (also called Drabkin's reagent, contains potassium cyanide) has most probably not been reported so far. Here we report a rare case of acute cyanide poisoning in a 30-year-old female laboratory technician resulting from deliberate ingestion of commercially available, ready to use liquid cyanmethemoglobin reagent used for colorimetric determination of hemoglobin in blood. She made an uneventful recovery with treatment.

New approaches in tail-bleeding assay in mice: improving an important method for designing new anti-thrombotic agents.

This report describes a modified, simple, low-cost and more sensitive method to determine bleeding patterns and haemoglobin concentration in a tail-bleeding assay using BALB/c mice and tail tip amputation. The cut tail was immersed in Drabkin's reagent to promote erythrocyte lysis and haemoglobin release, which was monitored over 30min. The operator was blinded to individual conditions of the mice, which were treated with either saline (NaCl 0.15m), DMSO (0.5%) or clinical anti-thrombotic drugs. Our experimental protocols showed good reproducibility and repeatability of results when using Drabkin's reagent than water. Thus, the use of Drabkin's reagent offered a simple and low-cost method to observe and quantify the bleeding and rebleeding episodes. We also observed the bleeding pattern and total haemoglobin loss using untreated animals or those under anti-coagulant therapy in order to validate the new Drabkin method and thus confirm that it is a useful protocol to quantify haemoglobin concentrations in tail-bleeding assay. This modified method provided a more accurate results for bleeding patterns in mice and for identifying new anti-thrombotic drugs.

Comparative measuring between fresh and stored Drabkin′s reagent preparations on hemoglobin estimation

This pilot case control hospital base study was conducted to determine the effect of using stored Drabkin's reagent on hemoglobin estimation compared with freshly prepared Drabkin's reagent. Freshly 50 ethylenediaminetetraacetic acid venous blood samples were collected from volunteers from Omdurman Military Hospital, Sudan, the Hb estimation performed using manual method (Hemiglobincyanide or cyanmethemoglobin method), Drabkin's used was prepared in a manner (fresh, 4 days, 8 days and 12 days stored Drabkin's). Then the collected data were analyzed by SPSS computer program. The result shows that the mean concentration of Hb (g/dL) when estimated by prepared Drabkin's reagent for several interval, the fresh reagent result was 13.0 g/dL, 4 days was reagent 11.9 g/dL, 8 days reagent was 11.4 g/dL and 12 days reagent was 11.3 g/dL. The study reveals that the mean of Hb when measured by 4 days stored Drabkin's reagent were statically insignificant and significant when measured by 8 days and 12 days stored Drabkin's reagent ( P = 0.05).

Simple Paper-Based Test for Measuring Blood Hemoglobin Concentration in Resource-Limited Settings

The measurement of hemoglobin concentration ([Hb]) is performed routinely as a part of a complete blood cell count to evaluate the oxygen-carrying capacity of blood. Devices currently available to physicians and clinical laboratories for measuring [Hb] are accurate, operate on small samples, and provide results rapidly, but may be prohibitively expensive for resource-limited settings. The unavailability of accurate but inexpensive diagnostic tools often precludes proper diagnosis of anemia in low-income developing countries. Therefore, we developed a simple paper-based assay for measuring [Hb]. A 20-μL droplet of a mixture of blood and Drabkin reagent was deposited onto patterned chromatography paper. The resulting blood stain was digitized with a portable scanner and analyzed. The mean color intensity of the blood stain was used to quantify [Hb]. We compared the performance of the paper-based Hb assay with a hematology analyzer (comparison method) using blood samples from 54 subjects. The values of [Hb] measured by the paper-based assay and the comparison method were highly correlated (R(2) = 0.9598); the standard deviation of the difference between the two measurements was 0.62 g/dL. The assay was accurate within 1 g/dL 90.7% of the time, overestimating [Hb] by ≥1 g/dL in 1.9% and underestimating [Hb] by ≥1 g/dL in 7.4% of the subjects. This study demonstrates the feasibility of the paper-based Hb assay. This simple, low-cost test should be useful for diagnosing anemia in resource-limited settings, particularly in the context of care for malaria, HIV, and sickle cell disease patients in sub-Saharan Africa.

Altered Angiogenesis in Caveolin-1 Gene–Deficient Mice Is Restored by Ablation of Endothelial Nitric Oxide Synthase

Caveolin-1 is an essential structural protein of caveolae, specialized plasma membrane organelles highly abundant in endothelial cells, where they regulate multiple functions including angiogenesis. Caveolin-1 exerts a tonic inhibition of endothelial nitric oxide synthase (eNOS) activity. Accordingly, caveolin-1 gene-disrupted mice have enhanced eNOS activity as well as increased systemic nitric oxide (NO) levels. We hypothesized that excess eNOS activity, secondary to caveolin deficiency, would mediate the decreased angiogenesis observed in caveolin-1 gene-disrupted mice. We tested tumor angiogenesis in mice lacking either one or both proteins, using in vitro, ex vivo, and in vivo assays. We show that endothelial cell migration, tube formation, cell sprouting from aortic rings, tumor growth, and angiogenesis are all significantly impaired in both caveolin-1-null and eNOS-null mice. We further show that these parameters were either partially or fully restored in double knockout mice that lack both caveolin-1 and eNOS. Furthermore, the effects of genetic ablation of eNOS are mimicked by the administration of the NOS inhibitor N-nitro-L-arginine methyl ester hydrochloride (L-NAME), including the reversal of the caveolin-1-null mouse angiogenic phenotype. This study is the first to demonstrate the detrimental effects of unregulated eNOS activity on angiogenesis, and shows that impaired tumor angiogenesis in caveolin-1-null mice is, at least in part, the result of enhanced eNOS activity.

Combination Treatment with HER-2 and VEGF Peptide Mimics Induces Potent Anti-tumor and Anti-angiogenic Responses in Vitro and in Vivo

HER-2 is a member of the EGF receptor family and is overexpressed in 20-30% of breast cancers. HER-2 overexpression causes increased expression of VEGF at both the RNA and protein levels. HER-2 and VEGF are therefore considered good targets for cancer treatment, which has led to the development of two humanized monoclonal antibodies (mAb) pertuzumab and bevacizumab. Although passive immunotherapy with these Abs are approved for treatment of advanced breast cancer, a number of concerns exist. Treatment is expensive, has a limited duration of action, and is usually accompanied by serious side effects. We hypothesized that therapy with conformational peptide mimics aimed at blocking receptor-ligand interaction is potentially safer with little toxicity, cheaper with a longer half-life, and has greater penetrating abilities than mAbs. We designed and synthesized peptides based on the binding of HER-2 with pertuzumab and VEGF with VEGFR2. We show that treatment with the peptide mimics induces potent anti-tumor responses in vitro as determined by cell viability, proliferation, and HER2 phosphorylation assays. We also demonstrate in a transplantable BALB/c mouse tumor model that treatment with the peptide mimics resulted in a greater delay in tumor growth and development. Similarly, treatment with the peptide mimics inhibited angiogenesis in vivo as assessed by a Matrigel plug assay. To address the problem of degradability of L-amino acid peptides in vivo, we synthesized the retro-inverso D-peptide mimics that resulted in higher efficacy in treatment. Our study shows that combination treatment with HER-2 and VEGF peptide mimics provides greater efficacy than individual treatments.

Histone Deacetylase 9 Activates γ-Globin Gene Expression in Primary Erythroid Cells

Strategies to induce fetal hemoglobin (HbF) synthesis for the treatment of β-hemoglobinopathies probably involve protein modifications by histone deacetylases (HDACs) that mediate γ-globin gene regulation. However, the role of individual HDACs in globin gene expression is not very well understood; thus, the focus of our study was to identify HDACs involved in γ-globin activation. K562 erythroleukemia cells treated with the HbF inducers hemin, trichostatin A, and sodium butyrate had significantly reduced mRNA levels of HDAC9 and its splice variant histone deacetylase-related protein. Subsequently, HDAC9 gene knockdown produced dose-dependent γ-globin gene silencing over an 80-320 nm range. Enforced expression with the pTarget-HDAC9 vector produced a dose-dependent 2.5-fold increase in γ-globin mRNA (p < 0.05). Furthermore, ChIP assays showed HDAC9 binding in vivo in the upstream Gγ-globin gene promoter region. To determine the physiological relevance of these findings, human primary erythroid progenitors were treated with HDAC9 siRNA; we observed 40 and 60% γ-globin gene silencing in day 11 (early) and day 28 (late) progenitors. Moreover, enforced HDAC9 expression increased γ-globin mRNA levels by 2.5-fold with a simultaneous 7-fold increase in HbF. Collectively, these data support a positive role for HDAC9 in γ-globin gene regulation.

AP-1 (Fra-1/c-Jun)-mediated Induction of Expression of Matrix Metalloproteinase-2 Is Required for 15(S)-Hydroxyeicosatetraenoic Acid-induced Angiogenesis

To understand the involvement of matrix metalloproteinases (MMPs) in 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE)-induced angiogenesis, we have studied the role of MMP-2. 15(S)-HETE induced MMP-2 expression and activity in a time-dependent manner in human dermal microvascular endothelial cells (HDMVECs). Inhibition of MMP-2 activity or depletion of its levels attenuated 15(S)-HETE-induced HDMVEC migration, tube formation, and Matrigel plug angiogenesis. 15(S)-HETE also induced Fra-1 and c-Jun expression in a Rac1-MEK1-JNK1-dependent manner. In addition, 15(S)-HETE-induced MMP-2 expression and activity were mediated by Rac1-MEK1-JNK1-dependent activation of AP-1 (Fra-1/c-Jun). Cloning and site-directed mutagenesis of MMP-2 promoter revealed that AP-1 site proximal to the transcriptional start site is required for 15(S)-HETE-induced MMP-2 expression, and Fra-1 and c-Jun are the essential components of AP-1 that bind to MMP-2 promoter in response to 15(S)-HETE. Hind limb ischemia led to an increase in MEK1 and JNK1 activation and Fra-1, c-Jun, and MMP-2 expression resulting in enhanced neovascularization and recovery of blood perfusion in wild-type mice as compared with 12/15-Lox(-/-) mice. Together, these results provide the first direct evidence for a role of 12/15-Lox-12/15(S)-HETE axis in the regulation of ischemia-induced angiogenesis.

Mitigation of surfactant erythrocyte toxicity by egg phosphatidylcholine.

Polyoxyethylene alkyl ether surfactants have been shown to have excellent penetration enhancing abilities although they are associated with a high level of local toxicity. We have compared the toxicity of a range of polyoxyethylene alkyl ethers (Brij 96, Brij 76, Brij 56, 10 lauryl ether and 9 lauryl ether) to an anionic surfactant (sodium dodecyl sulphate (SDS)), an ampholytic surfactant (lysophosphatidylcholine) and a cationic surfactant (tetradecyltrimethylammonium bromide (TTAB)), in the presence and absence of egg phosphatidylcholine. The toxicity of the surfactants or phospholipid/surfactant mixtures was assessed by measuring haemolytic activity. The test samples were incubated with a suspension of red blood cells for 30 min and Drabkin's reagent was used to indicate the amount of haemoglobin released. All of the polyoxyethylene alkyl ethers, SDS, TTAB and lysophosphatidylcholine exhibited haemolytic activity at concentrations between 0.10 and 0.25 mM. The addition of egg phosphatidylcholine reduced the toxicity for all of the surfactants, with the toxicity of Brij 96 being mitigated to a greater extent than the toxicity of the other polyoxyethylene surfactants examined. The rate of haemolysis induced by Brij 96 or 10 lauryl ether was also reduced by increasing concentrations of phosphatidylcholine. As the phosphatidylcholine content of a mixed surfactant system comprising egg phosphatidylcholine: Brij 96 was replaced by lysophosphatidylcholine and fatty acid, the haemolytic action of the mixture increased markedly. The results from this study show that the toxicity of surfactants to erythrocytes can be mitigated by the addition of egg phosphatidylcholine. Synthetic surfactants combined with phosphatidylcholine may generate drug delivery systems worthy of more extensive investigation.

Flea blood feeding patterns in cats treated with oral nitenpyram and the topical insecticides imidacloprid, fipronil and selamectin

A series of studies was conducted to determine the effect of systemically and topically active insecticides on blood consumption by fleas ( Ctenocephalides felis). Infestations were conducted by placing fleas into plexi-glass chambers attached to the lateral rib cage of domestic short-hair cats. After pre-defined periods, fleas and flea feces were extracted using vacuum aspiration and spectrophotometrically analyzed for hemoglobin using Drabkin's reagent. To determine how rapidly nitenpyram kills actively feeding fleas, a single oral treatment was administered 24 h after infestation. To determine the effect of nitenpyram on blood consumption of newly acquired fleas, cats were infested with fleas 1 h post-treatment and fleas and flea feces from both studies were extracted at 15, 30, 60, 120, 240 and 480 min post-treatment or post-infestation. To compare the effects of topically versus systemically active insecticides, 20 cats each with 2 chambers attached, were randomly allocated among groups and were infested with fleas 1 h after each of 4 nitenpyram treatments, or at 7, 14, 21 and 28 days after a single application of commercial spot-on formulations of fipronil, imidacloprid or selamectin. Infestations were also completed for untreated (control) cats. Twenty-four hours after infestation, fleas and flea feces were removed for host blood quantification. If at any time, flea blood consumption in a treated group did not significantly differ from that of fleas infesting controls, that treatment group was withdrawn from the study. Nitenpyram effects on actively feeding fleas were first observed at 60 min post-dosing when 38% of fleas were dead or moribund, and at 240 min 100% were dead or moribund. Nitenpyram produced a significant reduction in flea blood consumption ( p < 0.05), which appeared to cease 15 min after infestation. For the treatment comparisons, significantly more ( p < 0.05) blood was consumed by fleas taken from imidacloprid and fipronil-treated cats than from the nitenpyram or selamectin groups. Only on nitenpyram- or selamectin-treated cats were there significant reductions ( p < 0.05) in flea blood consumption on days 21 and 28, with significant difference ( p > 0.05) between these two groups on day 28. In this study systemically acting insecticides such as nitenpyram, and the topically applied but systemically active insecticide selamectin, were more effective in interfering with flea blood feeding than were imidacloprid and fipronil.

Fibroblast Growth Factor-2 Is a Downstream Mediator of Phosphatidylinositol 3-Kinase-Akt Signaling in 14,15-Epoxyeicosatrienoic Acid-induced Angiogenesis

To determine the efficacy of cytochrome P450 2C9 metabolites of arachidonic acid, viz. 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs), in inducing angiogenesis, we have studied their effects on human dermal microvascular endothelial cell (HDMVEC) tube formation and migration. All four EETs stimulated HDMVEC tube formation and migration in a dose-dependent manner. Because 14,15-EET was found to be slightly more efficacious than 5,6-, 8,9-, and 11,12-EETs in stimulating HDMVEC tube formation and migration, we next focused on elucidation of the signaling mechanisms underlying its angiogenic activity. 14,15-EET stimulated Akt and S6K1 phosphorylation in Src- and phosphatidylinositol 3-kinase (PI3K)-dependent manner in HDMVECs. Inhibition of Src and PI3K-Akt-mTOR signaling by both pharmacological and dominant-negative mutant approaches suppressed 14,15-EET-induced HDMVEC tube formation and migration in vitro and Matrigel plug angiogenesis in vivo. In addition, 14,15-EET induced the expression of fibroblast growth factor-2 (FGF-2) in Src- and PI3K-Akt-dependent and mTOR-independent manner in HDMVECs. Neutralizing anti-FGF-2 antibodies completely suppressed 14,15-EET-induced HDMVEC tube formation and migration in vitro and Matrigel plug angiogenesis in vivo. Together, these results show for the first time that Src and PI3K-Akt signaling via targeting in parallel with FGF-2 expression and mTOR-S6K1 activation plays an indispensable role in 14,15-EET-induced angiogenesis.

Spectrophotometric Method of Quantifying Adult Cat Flea (Siphonaptera: Pulicidae) Feces

Cat flea, Ctenocephalides felis felis (Bouché), feces are an essential part of larval nutrition under natural conditions. The mass values of adult flea feces can be measured by dissolving samples of flea feces in Drabkin's reagent, filtering, centrifuging, and measuring absorbance spectrophotometrically at 540 nm. Either flea feces or air-dried host blood can be used to generate the standard curve used to convert absorbance (optical density) values into mass values. Debris collected from flea-infested house cats averaged 23.02 mg debris per cat per h with an average of 10.41 mg flea feces per cat per h. Flea feces deposited in the environment serve as potential larval food. Adult flea feces comprised an average of 44.28% of the debris deposited from infested domestic house cats in this study.

A comparison of the effects of Drabkin's reagent and mercaptosuccinate on the assay of erythrocyte glutathione peroxidase

A comparison of the effects of Drabkin's reagent and mercaptosuccinate on the assay of erythrocyte glutathione peroxidase

Nutritional Profile of Saudi Primary Schoolgirls in an Urban Region

Two hundred eighty-five primary schoolgirls from the urban area of Thugba, Al-Khobar, in the Eastern Province of Saudi Arabia were examined anthropometrically. Hemoglobin estimations and laboratory...

Blood glutathione peroxidase

Manual and automated assays for the determination of glutathione peroxidase activity in bovine, sheep, pig, and human blood samples are described. The reactivation of the enzyme in blood samples after storage at -20°C was examined. Cyanide and Drabkin's reagent, as used to prepare hemolysates in other assays, have been shown to inhibit enzyme activity, particularly in stored blood samples, and is omitted from this assay.

A new reagent for the rapid determination of total hemoglobin as hemiglobincyanide in blood containing carboxyhemoglobin

Kinetics of conversion of HbCO to HiCN with various K 3Fe(CN) 6—KCN reagents was examined photometrically. Complete conversion of HbCO to HiCN required about 8 hr, 150 min, and 50 min with Drabkin's reagent, that of van Kampen and Zijlstra, and that of Taylor and Miller, respectively. The absorbance at 540 nm was stabilized practically in 5 min even in CO-saturated blood when a reagent containing a 1600-fold excess of K 3Fe(CN) 6 to Hb iron was used. A slight increase in the absorbance was observed around 504 nm in the HiCN solution produced with the reagent. The absorbance at 540 nm in the solution, however, was stable until at least 120 min after mixing. From these findings, a reagent containing a 1600-fold excess of K 3Fe(CN) 6 to Hb iron and an incubation time of 5 min were used for the complete conversion of HbCO to HiCN. The stabilization of the absorbance at 540 nm was often prolonged to 10 min when the reagent was stored over 2 weeks. The reagent was compared with two other reagents, using 20 blood samples containing various amounts of HbCO, and proved to be suitable for the determination of total Hb in blood containing elevated HbCO as well as in ordinary blood.