Ferrous Ascorbate Research Articles

Different iron sources to study the physiology and biochemistry of iron metabolism in marine micro-algae

We compared ferric EDTA, ferric citrate and ferrous ascorbate as iron sources to study iron metabolism in Ostreococcus tauri, Phaeodactlylum tricornutum and Emiliania huxleyi. Ferric EDTA was a better iron source than ferric citrate for growth and chlorophyll levels. Direct and indirect experiments showed that iron was much more available to the cells when provided as ferric citrate as compared to ferric EDTA. As a consequence, growth media with iron concentration in the range 1–100 nM were rapidly iron-depleted when ferric citrate—but not ferric EDTA was the iron source. When cultured together, P. tricornutum cells overgrew the two other species in iron-sufficient conditions, but E. huxleyi was able to compete other species in iron-deficient conditions, and when iron was provided as ferric citrate instead of ferric EDTA, which points out the critical influence of the chemical form of iron on the blooms of some phytoplankton species. The use of ferric citrate and ferrous ascorbate allowed us to unravel a kind of regulation of iron uptake that was dependent on the day/night cycles and to evidence independent uptake systems for ferrous and ferric iron, which can be regulated independently and be copper-dependent or independent. The same iron sources also allowed one to identify molecular components involved in iron uptake and storage in marine micro-algae. Characterizing the mechanisms of iron metabolism in the phytoplankton constitutes a big challenge; we show here that the use of iron sources more readily available to the cells than ferric EDTA is critical for this task.Electronic supplementary materialThe online version of this article (doi:10.1007/s10534-013-9688-1) contains supplementary material, which is available to authorized users.

English

Malaria in pregnancy is a significant contributor to adverse pregnancy outcome. In low resource setting of India to contain malaria in the vast chloroquine resistant endemic zone LLIN (Long lasting insecticide treated Nets) has been introduced as an intervention to prevent malarial morbidity and mortality in the population among anemic pregnant women in malarias zone is quite high, oral ferrous ascorbate has an edge over commonly available ferrous sulfate to rectify Anemia with least side effect in those pregnant women. INTRODUCTION: Malaria in pregnancy is an important public health problem that affects 25 million pregnant women in endemic zones of world and contributes heavily on maternal and infant morbidity and mortality. Acquired immunity in endemic zones is compromised in pregnant state. Maternal Anemia (70%) still birth, premature birth and LBW are adverse outcome in pregnant women in endemic zones of Malaria, especially in chloroquine resistant areas. Although in 2004 WHO recommended prophylactic two doses of sulfadoxine pyrimethamine (Ref-5) in 2nd trimester of pregnancy in endemic zones, sub optimal drug adherence and increasing sulfadoxine pyrimethamine resistance has stood as an obstacle for Malaria containment. Now effect of long lasting insecticide net (LLIN) insecticide treated net (ITN) is being promoted through UNICEF and Govt. in endemic zones resistant to chloroquine chemoprophylaxis. Here is a camp based study in one heavily affected Malarias zone of Odisha on effect of LLIN in pregnant women and effect of Oral ferrous Ascorbate in improving the anaemic status of pregnant women in malarious zone. MATERIALS & METHODS: Ramagiri PHC was selected for study as it comes under Intensive Falciparum zone of Koraput district, API-32 in 2012. A pre-camp advertisement in the area was performed. A three member doctor team along with four paramedical assistants, one lab technician and two Divine Life Society volunteers were employed for the camp and 100 nos. of Antenatal cases were registered out of which only 50 cases were randomly studied whose socio economic status was noted to be poor. Antenatal check up Height of Uterus, Abdominal girth/ Wt, BP, HB, urine ALB, splenic examination and Cervical smear and peripheral blood smear were studied. In all cases MP was studied by thick blood sample. Hemoglobin was instantly estimated by hemocue instrument (HB301) after finger prick. Only 10 cases gave their consent for vaginal cytology inspite of maintenance of privacy in presence of a female attendant. Ferrous sulfate 45 tab and Ferrous Ascorbate (Elferri xt supplied by Svizera Health Care - Constituent Per tab Ferrous Ascorbate 100 mg, Folic Acid-1.5 mg, Zinc -22.5 mg ) 45 tabs were given on alternate making them Group 'A' and Group 'B' respectively. HB was reestimated after 45 days in both groups by same

Is a 40 % Absorption of Iron from a Ferrous Ascorbate Reference Dose Appropriate to Assess Iron Absorption Independent of Iron Status?

Although a 40% absorption of a standard reference dose corresponds to iron (Fe) absorption in borderline Fe-deficient subjects, this percentage is currently applied to all subjects independent of Fe status: (a) to assess the use of the 40% of Fe absorption of the reference dose (FeRD%) for subjects with iron-depleted stores (IDS), normal Fe status (NIS), Fe deficiency without anemia (IDWA), and Fe deficiency anemia (IDA) and (b) to explore relationships between Fe status biomarkers and FeRD%. Six hundred forty-six participants (582 women and 64 men) were selected from multiple Fe bioavailability studies and classified into four groups based on Fe status: NIS, IDS, IDWA, and IDA. All men were classified as normal. The absorption from FeRD% was calculated in each group and correlated with Fe status biomarkers. (a) Women with IDS absorbed 40 (18.9-84.7) % of the reference dose; (b) for male subjects with NIS, the absorption of the reference dose was 19 (9.8-36.1) %, while for females, absorption was observed as to be 34(16.7-68.6)%. In the case of subjects with IDWA, a 43 (19.7-92.5) % absorption was observed, while subjects with IDA demonstrated 67 (45.2-98.6) % absorption. Serum ferritin (SF) had the strongest inverse correlation with FeRD% (r = -0.41, p < 0.001). A transferrin saturation (TS) <15% increases the probability that the FeRD% will be highly elevated (OR, 5.05; 95% CI, 2.73, 9.31; p < 0.001). A 40% absorption as reference dose is only appropriate to assess Fe absorption in subjects with IDS and IDWA. SF had an inverse correlation with FeRD%, and TS increases the probability that the FeRD% will be elevated by over fivefold.

Bioavailability of Stabilised Ferrous Gluconate with Glycine in Fresh Cheese Matrix: a Novel Iron Compound for Food Fortification

Iron fortification of foods continues to be one of the preferred ways of improving the iron status of the population. Dairy product is a common product in the diet; therefore, it is a plausible vehicle for iron fortification. This study aims to investigate the bioavailability of ferrous gluconate stabilised with glycine (FGSG) in a fresh cheese fortified with zinc. The iron bioavailability of fresh cheese fortified with either FGSG and with or without zinc and FGSG in aqueous solution and a water solution of ferrous ascorbate (reference dose) was studied using double radio iron ((55)Fe and (59)Fe) erythrocyte incorporation in 15 male subjects. All subjects presented with normal values for iron status parameters. The geometric mean of iron bioavailability for the water solution of FGSG was 38.2 %, adjusted to 40 % from reference doses (N.S.). Iron bioavailability in fresh cheese fortified with Ca and Zn was 15.4 % and was 23.1 % without Zn, adjusted to 40 % from reference doses (N.S.). The results of the present study show that the novel iron compound ferrous gluconate stabilised with glycine in a fresh cheese matrix is a good source of iron and can be used in iron fortification programmes.

Metabolic precursors and cofactors stimulate astaxanthin production in Paracoccus MBIC 01143

This work investigates bacterial production of astaxanthin as an alternative to production by algae and yeast owing to its lower incubation time and simpler downstream processing. The physical parameters and medium composition were optimized for astaxanthin production by Paracoccus MBIC 01143. The optimized media was supplemented with tricarboxylic acid intermediates to enhance the pool of precursors, while the cofactors of Crt enzymes (ferrous sulphate, ascorbate, NADPH, ATP, and 2-oxoglutarate) were added to stimulate their enzyme activity aiming at higher astaxanthin accumulation. Malate at 5 mM and ferrous sulphate at 1 mM increased the astaxanthin production from 177 to 3,750 μg/L.

Treatment of Iron Deficiency Anemia in Children: A Comparative Study of Ferrous Ascorbate and Colloidal Iron

To compare the efficacy of ferrous ascorbate and colloidal iron in the treatment of iron deficiency anemia in children. Eighty one children, aged 6mo to 12y, were screened for iron deficiency anemia (IDA) and those diagnosed with IDA were randomized to receive ferrous ascorbate or colloidal iron for a period of 12wk, such that each child received elemental iron 3mg/kg body weight/d. Increase in hemoglobin (Hb) level was the primary outcome measure. Assessment was performed at baseline, wk 4, wk 8 and wk 12. Of 81 children screened, 73 were included in the study. The mean rise in Hb at the end of the 12wk was significantly higher in ferrous ascorbate group than the colloidal iron group [3.59 ± 1.67g/dl vs. 2.43 ± 1.73g/dl; P < 0.01]. Significantly higher proportion of children receiving ferrous ascorbate (64.86% vs. 31.03%; P < 0.01) became non-anemic in comparison to colloidal iron. Ferrous ascorbate provides a significantly higher rise in hemoglobin levels in comparison to colloidal iron. The study supports the use of ferrous ascorbate in the pediatric age group, providing evidence for its role as an efficient oral iron supplement in the treatment of iron deficiency anemia.

Iron Deficiency Anemia in Pregnancy: Intravenous Versus Oral Route

The aim of this study was to compare the efficacy and safety of intravenous iron with oral iron in the treatment of iron deficiency anemia of pregnancy. A randomized experimental study was conducted at K. J. Somaiya Hospital involving 200 pregnant women with iron deficiency anemia. In the intravenous group iron dose was calculated from: Total iron dose required (mg)=2.4×weight kg×target hemoglobin-actual hemoglobin) g/dl+500. Target hemoglobin was set at 12g/dl. In the oral group patients received 200mg oral ferrous ascorbate daily. Hemoglobin and serum ferritin were reviewed at 2, 4, and 6weeks. Paired and independent t test was applied. The change in hemoglobin and ferritin levels from baseline was significantly higher in the intravenous group than the oral group at each measurement (P=0.000). Intravenous iron elevates hemoglobin and restores iron stores faster than oral iron, with no severe adverse reactions.

Comparison between Ferrous Ascorbate and Colloidal Iron in the Treatment of Iron Deficiency Anemia in Children from Kolkata, India

Comparison between Ferrous Ascorbate and Colloidal Iron in the Treatment of Iron Deficiency Anemia in Children from Kolkata, India

Comparison between Ferrous Ascorbate and Colloidal Iron in the Treatment of Iron Deficiency Anemia in Children from Kolkata, India

Aim: To compare the efficacy and safety of ferrous ascorbate and colloidal iron in children with iron deficiency anemia. Study Design: An open, randomized, comparative, parallel-group study.

Co-precipitation of Phosphate and Iron Limits Mitochondrial Phosphate Availability in Saccharomyces cerevisiae Lacking the Yeast Frataxin Homologue (YFH1)

Saccharomyces cerevisiae cells lacking the yeast frataxin homologue (Δyfh1) accumulate iron in the mitochondria in the form of nanoparticles of ferric phosphate. The phosphate content of Δyfh1 mitochondria was higher than that of wild-type mitochondria, but the proportion of mitochondrial phosphate that was soluble was much lower in Δyfh1 cells. The rates of phosphate and iron uptake in vitro by isolated mitochondria were higher for Δyfh1 than wild-type mitochondria, and a significant proportion of the phosphate and iron rapidly became insoluble in the mitochondrial matrix, suggesting co-precipitation of these species after oxidation of iron by oxygen. Increasing the amount of phosphate in the medium decreased the amount of iron accumulated by Δyfh1 cells and improved their growth in an iron-dependent manner, and this effect was mostly transcriptional. Overexpressing the major mitochondrial phosphate carrier, MIR1, slightly increased the concentration of soluble mitochondrial phosphate and significantly improved various mitochondrial functions (cytochromes, [Fe-S] clusters, and respiration) in Δyfh1 cells. We conclude that in Δyfh1 cells, soluble phosphate is limiting, due to its co-precipitation with iron.

Iron absorption and iron status are reduced after Roux-en-Y gastric bypass

BackgroundIron deficiency and iron deficiency anemia are common in patients who undergo gastric bypass. The magnitude of change in iron absorption is not well known. ObjectiveThe objective was to evaluate the effects of Roux-en-Y gastric bypass (RYGBP) on iron status and iron absorption at different stages after surgery. We hypothesized that iron absorption would be markedly impaired immediately after surgery and would not improve after such a procedure. DesignAnthropometric, body-composition, dietary, hematologic, and iron-absorption measures were determined in 67 severe and morbidly obese women [mean age: 36.9 ± 9.8 y; weight: 115.1 ± 15.6 kg, body mass index (BMI: in kg/m2); 45.2 ± 4.7] who underwent RYGBP. The Roux-en-Y loop length was 125–150 cm. Determinations were carried out before and 6, 12, and 18 mo after surgery. Fifty-one individuals completed all 4 evaluations. ResultsThe hemoglobin concentration decreased significantly throughout the study (repeated-measures analysis of variance). The percentage of anemic subjects changed from 1.5% at the beginning of the study to 38.8% at 18 mo. The proportion of patients with low serum ferritin increased from 7.5% to 37.3%. The prevalence of iron deficiency anemia was 23.9% at the end of the experimental period. Iron absorption from both a standard diet and from a standard dose of ferrous ascorbate decreased significantly after 6 mo of RYGBP to 32.7% and 40.3% of their initial values, respectively. No further significant modifications were noted. ConclusionIron absorption is markedly reduced after RYGBP with no further modifications, at least until 18 mo after surgery.

Cooperative functions of manganese and thiol redox system against oxidative stress in human spermatozoa

AIMS:In this study, the effects of 0.1 mM Mn2+ on thiol components (total thiols [TSH], glutathione reduced [GSH], glutathione oxidized [GSSG] and redox ratio [GSH/ GSSG]) have been determined in human spermatozoa.SETTINGS AND DESIGN:The subjects of the study were healthy males having more than 75% motility and 80 × 106 sperms/mL.MATERIALS AND METHODS:Fresh semen was suspended in phosphate-buffered saline (PBS) (pH 7.2) and this suspension was divided into eight equal fractions. All fractions, control (containing PBS) and experimental (treated/untreated with [ferrous ascorbate, FeAA - 200 FeSO4 μM, 1000 μM ascorbic acid, nicotine (0.5 mM) and FeAA + nicotine], supplemented/unsupplemented with Mn2+ [0.1 mM]), were incubated for 2 h at 37°C. These fractions were assessed for determining the thiol components.STATISTICAL ANALYSIS:The data were statistically analyzed by Students “t” test.RESULTS AND CONCLUSIONS:Ferrous ascorbate, nicotine and ferrous ascorbate + nicotine induced oxidative stress and decreased GSH and redox ratio (GSH/GSSG ratio) but increased the TSH and GSSG levels. Mn2+ supplementation improved TSH, GSH and redox ratio (GSH/GSSG) but decreased the GSSG level under normal and oxidative stress conditions. Thiol groups serve as defense mechanisms of sperm cells to fight against oxidative stress induced by stress inducers such as ferrous ascorbate, nicotine and their combination (ferrous ascorbate + nicotine). In addition, Mn2+ supplementation maintains the thiol level by reducing oxidative stress.

Mn2+: A potent antioxidant and stimulator of sperm capacitation and acrosome reaction in crossbred cattle bulls

Abstract. Manganese is a well known antioxidant and is a potent inhibitor of in vitro oxidative stress. The aim of this work was to study the influence of Mn2+ (60 μM) on capacitation and acrosome reaction of crossbred cattle bull spermatozoa. Fresh semen was centrifuged and pellet so obtained was suspended in TALP medium (pH 7.4). The sperm suspension was divided into four equal fractions(four tubes). In the control tube, only TALP was added; whereas the remaining three tubes were supplemented with ferrous ascorbate (FeAA – 150 μM FeSO4 : 750 μM ascorbic acid) , 60 μM Mn2+ and FeAA+ Mn2+, respectively. All fractions were incubated incubated (37 °C) for 6 hr in CO2 incubator. These fractions were assessed for morphology, % hyperactivity, lipid peroxidation (LPO) and % acrosome reaction. Morphology of the capacitated spermatozoa remained unaltered with FeAA/Mn2+/FeAA+Mn2+ treatments. FeAA treatment non-significantly (p ≥ 0.05) decreased % sperm hyperactivity % acrosome reaction, but, increased the LPO level. Supplementation of Mn2+ increased % hyperactivity and % acrosome reaction significantly (p ≤ 0.05) in FeAA untreated fractions, but, non-significantly (p ≥ 0.05) in FeAA treated fractions. Malondialdehyde (MDA – end product of LPO) decreased significantly (p ≤ 0.05) with the Mn2+ supplementation both in FeAA treated and untreated fractions. It is concluded that Mn2+ protects the bull sperm against LPO/oxidative stress and facilitates the occurrence of capacitation and acrosome reaction.

Antioxidant-mediated protective effect of potato peel extract in erythrocytes against oxidative damage

Potato peels are waste by-product of the potato processing industry. They are reportedly rich in polyphenols. Our earlier studies have shown that extracts derived from potato peel (PPE) possess strong antioxidant activity in chemical and biological model systems in vitro, attributable to its polyphenolic content. The main objective of this study was to investigate the ability of PPE to protect erythrocytes against oxidative damage, in vitro. The protection rendered by PPE in erythrocytes was studied in terms of resistance to oxidative damage, morphological alterations as well as membrane structural alterations. The total polyphenolic content in PPE was found to be 3.93 mg/g powder. The major phenolic acids present in PPE were predominantly: gallic acid, caffeic acid, chlorogenic acid and protocatechuic acid. We chose the experimental prooxidant system: FeSO 4 and ascorbic acid to induce lipid peroxidation in rat RBCs and human RBC membranes. PPE was found to inhibit lipid peroxidation with similar effectiveness in both the systems (about 80–85% inhibition by PPE at 2.5 mg/ml). While PPE per se did not cause any morphological alteration in the erythrocytes, under the experimental conditions, PPE significantly inhibited the H 2O 2-induced morphological alterations in rat RBCs as revealed by scanning electron microscopy. Further, PPE was found to offer significant protection to human erythrocyte membrane proteins from oxidative damage induced by ferrous–ascorbate. In conclusion, our results indicate that PPE is capable of protecting erythrocytes against oxidative damage probably by acting as a strong antioxidant.

The influence of organic and inorganic Fe supplementation on red blood picture, immune response and quantity of iron in organs of broiler chickens

The aim of this study was to investigate the influence of organic and inorganic Fe supplementation on red blood picture, immune response and quantity of iron in organs of broiler chickens. The trial was conducted on 200 'Arbor Acres' chickens randomly alloted in four equal groups. Birds from all groups were fed standard broiler feed, supplemented with 40 mg/kg of Fe originating from different sources: Group I (FeSO4), Group II (Fe bounded to yeast), Group III (ferrous ascorbate) and Group IV (iron chelate). From each group, 10 birds were sacrificed on 21st, 35th and 42nd day and the following parameters were measured: erythrocyte count, hematocrite value, hemoglobin concentration, concentration of nonheme iron in spleen, liver and bone marrow (femur), degree of cutaneous hypersensitivity to PHA and titers of antibodies to Gumboro virus following vaccination. Addition of organic iron supplements resulted in increased erythrocyte count, hemoglobin concentration and hematocrite value on the 21st day. Different iron forms did not change the concentration of nonheme iron in the liver on the 21st and 42nd day. On the 35th day, the group supplemented with ferrous ascorbate had lower liver iron concentration. Also, concentrations of nonheme iron in the spleen were lower in groups supplemented with organic iron forms. The concentration of iron in the bone marrow decreased with age and the lowest values were recorded in the ferrous ascorbate supplemented group. The degree of cutaneous hypersensitivity to PHA was higher in groups supplemented with organic iron forms on the 21st and 35th day. Titers of anti-Gumboro antibodies were higher in the group supplemented with iron helate on the 35th day, but later (day 42) no significant differences were observed among groups. .

Effect of ferrous sulphate and ascorbic acid on motility, viability and lipid peroxidation of crossbred cattle bull spermatozoa

Numerous factors influence male fertility, one of these being the oxidative stress, which has elicited enormous interest recently. In sperm, induction of oxidation decreases motility and viability but increases lipid peroxidation (LPO). The optimum dose of ferrous ascorbate (FeAA: FeSO4 + ascorbic acid) for inducing oxidative stress by affecting motility, viability and LPO has been ascertained in local crossbred cattle bull spermatozoa. The fractions of spermatozoa suspended in 2.9% sodium citrate were subjected to three doses of FeAA (100 : 500, 150 : 750, 200 : 1000; μmol/l FeSO4 : μmol/l ascorbic acid). These fractions were assessed for various parameters. Increase in the incubation period and promoter concentration induced a decrease in motility and viability, but an increase in LPO. Among three doses of FeAA, 150 : 750 μmol/l ascorbic acid is suggested to be the optimum/best dose as it induces the oxidative stress/LPO to a significant extent and also maintains better motility and viability as compared with the other two doses, and such conditions may enhance the fertilising potential of bull spermatozoa.

Oxidative stress alters membrane sulfhydryl status, lipid and phospholipid contents of crossbred cattle bull spermatozoa

Ferrous ascorbate (FeAA: FeSO 4 + ascorbic acid) has been used in the past by different investigators to induce oxidative stress. The optimum dose of FeAA for inducing oxidative stress by affecting thiols [total thiols (TSH), glutathione reduced (GSH), glutathione oxidized (GSSG), redox ratio (GSH/GSSG)], total lipids and phospholipids has been ascertained in the local crossbred cattle bull spermatozoa. The fractions of spermatozoa suspended in 2.9% sodium citrate were subjected to three doses of FeAA (100 μM:500 μM, 150 μM:750 μM, 200 μM:1000 μM; FeSO 4:ascorbic acid), and were assessed for various parameters. On increasing the concentration of FeAA, a gradual decrease in TSH, GSH, GSH/GSSG, lipid and phospholipid levels, but increase in GSSG content were observed. It is concluded that thiol groups play an important role in antioxidation and detoxification of ROS as well as maintaining intracellular redox status. Thiol groups, thus, serve as defense mechanisms of sperm cells to fight against oxidative stress. In addition, all doses of FeAA cause leakage of lipids and phospholipids from the bull sperm membranes.

Persistent anemia after Roux-en-Y gastric bypass

Objective We report the case of a 42-y-old morbidly obese woman who presented persistent anemia as result of Roux-en-Y gastric bypass. Methods The surgical procedure conducted in 1999 consisted of horizontal gastroplasty with truncular vagotomy, Roux-en-Y gastrojejunal anastomosis with an alimentary limb of 60 cm, and cholecystectomy. In 2000 a second surgery (subtotal gastrectomy, i.e., 90%, with a 50-mL gastric pouch) was performed because of failed gastroplasty. Anemia was detected approximately 1 y after the second surgery. This condition worsened significantly after an abdominal lipectomy performed in 2001. Since then, different oral iron compounds were used for treatment, but with unsatisfactory results. The subject was anemic for 4 y. Results The condition was corrected only after intravenous iron administration. Iron absorptions from 3 mg of iron as ferrous ascorbate and from a standardized diet that also contained 3 mg of iron were 48.4% and 39.9%, respectively. Conclusion Iron absorption tests provided evidence that the reduction of intestinal iron absorption capacity was the most probable cause of the persistent anemia.

The influence of organic and inorganic Fe supplementation on productivity of broilers

The aim of this study was to investigate the influence of organic and inorganic Fe supplementation on productivity of broiler chickens. The trial was conducted on 200 Arbor Acres chickens divided into four equal groups. Birds from all groups were fed standard broiler feed, supplemented with 40 mg/kg of Fe originating from different sources: Group I (FeSO4), Group II (Fe bound to yeast), Group III (ferrous ascorbate) and Group IV (iron chelate). From each group, 10 birds were sacrificed on the 21st, 35th and 42nd day and the following parameters were measured: body mass, daily body mass gain, food consumption and conversion rate. At the end of the trial, the highest average body mass was measured in the group supplemented with ferrous ascorbate (15,51% higher when compared with the group supplemented with FeSO4). The conversion rate was lower in birds supplemented with organic iron forms and had the lowest value in the group supplemented with ferrous ascorbate.

15 EFFECT OF BULL EPIDIDYMIS STORAGE CONDITIONS ON CRYOPRESERVED EPIDIDYMAL SPERM IN VITRO FERTILITY AND LIPID PEROXIDATION STATUS

Although cryopreservation of epididymal sperm has been studied extensively in several species, some factors that could negatively influence its quality are still unknown, such as the storage conditions of the epididymides prior to sperm collection. Studies indicate that the lower the storage temperature, the better the sperm quality after collection (Kaabi et al. 2003 Theriogenology 60, 1249–1259). An additional factor is lipid peroxidation in which sperm membrane resistance against reactive oxygen species (ROS) attacks is an important component. The objective of this experiment was to study whether the epididymis storage temperature following slaughter, as well as the intrinsic resistance against oxidative stress, affects the fertilizing capacity of cryopreserved epididymal bull sperm in vitro. Twelve epididymides (6 bulls) were collected after slaughter and divided into 2 groups, (stored at either 4 or 37�C for 2), after which semen was collected from the caudae epididymides and cryopreserved. Subsequently, one aliquot of the frozen–thawed semen samples was subjected to induced lipid peroxidation with ferrous sulfate and ascorbate (37�C; 2 h), after which tiobarbituric acid-reactive substances (TBARS), as an index of lipid peroxidation, were measured according to a method previously described (Beorlegui et al. 1997 Andrologia 29, 37–42). A second aliquot was used for in vitro fertilization in a routine IVF–IVC setup in duplicate (24-h maturation, SOF culture medium in 5% CO2, 5% O2, and 90% N2). In vitro embryo production results at Day 7 and TBARS levels were statistically analyzed using SAS (SAS Institute, Inc., Cary, NC, USA). No influence of storage temperature was observed at either TBARS level (4�C: 943.6 � 173.4; 37�C: 751.4 � 136.2 ng of TBARS/108 spermatozoa; P = 0.3) or on blastocyst rates (4�C: 23.0 � 2.8; 37�C: 18.7 � 3.6% of blastocysts; P = 0.2). However, the percentage of hatched blastocysts tend to be higher for epididymides stored at 4�C when compared to those stored at 37�C (6.4 � 1.8 and 2.3 � 0.9, respectively; P = 0.06). In addition, a negative correlation was found between TBARS concentrations and blastocyst rates (R = –0.57; P &amp;lt; 0.05). Compared to fresh samples collected from epididymides under the same conditions (unpublished data), levels of TBARS were two- to threefold higher for the cryopreserved sperm, indicating that lipid peroxidation appears to play a role in the decrease in quality of cryopreserved epididymal sperm. In conclusion, temperature during the epididymides short-term storage prior to sperm cryopreservation did not seem to influence the sperms&amp;apos; in vitro fertilizing capacity. On the other hand, an alternative to improve cryopreserved epididymal sperm in vitro fertility (or fertilizing capacity) could be the addition of antioxidants to semen extenders. Further studies are necessary to confirm this hypothesis.