Hematological responses to thermal acclimation in a cold water squaliform (Heterodontus francisci girard)

Summary The hematological modifications occurring as a result of acclimation to increased temperature in the cold water horn shark,Heterodontus francisci, were evaluated. Sharks were maintained under constant conditions except for temperature (15°C and 25°C) in a closed marine system. The total red blood cell (RBC) number decreased in the 25°C sharks. In contrast, hemoglobin concentration, hematocrit, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) significantly increased at 25°C compared to the control animals. RBC size was increased at 25°C, but the surface area/mm³ whole blood was reduced. Folic acid levels were not different between the groups. Vitamin B₁₂ levels decreased and testosterone increased at 25°C. Blood pH, number of erythroblasts, number of white blood cells (WBC) and WBC differential analyses were essentially unchanged at the two temperatures, except that the relative neutrophil number was increased. The major hematological changes occur in the erythrocytes and appear to be sequential in nature with an initial loss of RBC followed by increased hemoglobin synthesis and increased RBC size, but lack of recovery of RBC numbers.Abbreviations Hb hemoglobin - Hct hematocrit - MCH(C) mean corpuscular hemoglobin (concentration) - MCV mean corpuscular volume - RBC red blood cells - WBC white blood cells Contribution Number 359, Department of Biology     

Effects of lower body positive pressure on muscle sympathetic nerve activity response to head-up tilt

The present study was performed to test the hypothesis that application of lower body positive pressure (LBPP) during orthostasis would reduce the baroreflex-mediated enhancement in sympathetic activity in humans. Eight healthy young men were exposed to a 70 degrees head-up tilt (HUT) on application of 30 mmHg LBPP. Muscle sympathetic nerve activity (MSNA) was microneurographically recorded from the tibial nerve, along with hemodynamic variables. We found that in the supine position with LBPP, MSNA remained unchanged (13.4 +/- 3.3 vs. 11.8 +/- 2.3 bursts/min, without vs. with LBPP; P > 0.05), mean arterial pressure was elevated, but arterial pulse pressure and heart rate did not alter. At 70 degrees HUT with LBPP, the enhanced MSNA response was reduced (33.8 +/- 5.0 vs. 22.5 +/- 2.2 bursts/min, without vs. with LBPP; P < 0.05), mean arterial pressure was higher, the decreased pulse pressure was restored, and the increased heart rate was attenuated. We conclude that the baroreflex-mediated enhancement in sympathetic activity during HUT was reduced by LBPP. Application of LBPP in HUT induced an obvious cephalad fluid shift as well as a restoration of arterial pulse pressure, which reduced the inhibition of the baroreceptors. However, the activation of the intramuscular mechanoreflexes produced by 30 mmHg LBPP might counteract the effects of baroreflexes.     

Decreased Hematocrit-To-Viscosity Ratio and Increased Lactate Dehydrogenase Level in Patients with Sickle Cell Anemia and Recurrent Leg Ulcers

Leg ulcer is a disabling complication in patients with sickle cell anemia (SCA) but the exact pathophysiological mechanisms are unknown. The aim of this study was to identify the hematological and hemorheological alterations associated with recurrent leg ulcers. Sixty-two SCA patients who never experienced leg ulcers (ULC-) and 13 SCA patients with a positive history of recurrent leg ulcers (ULC+) - but with no leg ulcers at the time of the study – were recruited. All patients were in steady state condition. Blood was sampled to perform hematological, biochemical (hemolytic markers) and hemorheological analyses (blood viscosity, red blood cell deformability and aggregation properties). The hematocrit-to-viscosity ratio (HVR), which reflects the red blood cell oxygen transport efficiency, was calculated for each subject. Patients from the ULC+ group were older than patients from the ULC- group. Anemia (red blood cell count, hematocrit and hemoglobin levels) was more pronounced in the ULC+ group. Lactate dehydrogenase level was higher in the ULC+ group than in the ULC- group. Neither blood viscosity, nor RBC aggregation properties differed between the two groups. HVR was lower and RBC deformability tended to be reduced in the ULC+ group. Our study confirmed increased hemolytic rate and anemia in SCA patients with leg ulcers recurrence. Furthermore, our data suggest that although systemic blood viscosity is not a major factor involved in the pathophysiology of this complication, decreased red blood cell oxygen transport efficiency (i.e., low hematocrit/viscosity ratio) may play a role.     

Normal hematological values of the African neonate

A longitudinal study of normal hematological values of the newborn infant was undertaken in an effort to provide baseline data for assessing the African Neonate with hematological problems. There were 402 neonates, consisting of 304 full-term, 51 preterm and 47 post-term infants. The Hematocrit (Hct), Hemoglobin (Hb), Red Blood Cell Count (RBC), Reticulocyte count (Retic) and Nucleated Red Blood Cell Count (NRBC) were serially determined. The red cell indices, Mean corpuscular Hemoglobin (MCH), Mean Corpuscular volume (MCV) and Mean corpuscular Hemoglobin Concentration (MCHC) were calculated for each neonate. Our results showed that African neonates have lower hematological values than their North American and European counterparts. This was neither a reflection of an intrauterine anemia nor was it due to variables resulting from the timing of cord blood sampling. On the first day of life, the mean Hct was 45.4%; mean Hb was 15.46 gm/dl; and the RBC was 4.02 X 10(6) cells/mm2. The Retics, NRBC and other red blood cell indices do not differ from those of neonates reported from other parts of the world. We suggest therefore that the low hematological values of the African neonate may be intrinsic.     

Time course of hemorheological alterations after heavy anaerobic exercise in untrained human subjects.

The time course of hemorheological alterations was investigated after heavy anaerobic exercise in untrained male human subjects. The Wingate protocol was performed by each subject, and blood lactate, red blood cell (RBC) deformability and aggregation, white blood cell (WBC) activation, and several hematological parameters were investigated during 24 h after the exercise and compared with preexercise values. Compared with the preexercise value, blood lactate level was found to be approximately 10-fold higher immediately after the exercise. There was a transient, significant increment of RBC and WBC counts immediately after exercise that was followed by a decrement of RBC count. There was a second increase of WBC count, accompanied with increased percentages of granulocytes and granulocyte activation, starting 45 min after exercise. RBC deformability was found to be impaired immediately after exercise and remained reduced for at least 12 h; RBC aggregation was also found to be decreased after exercise, with the onset of this decrease delayed by 30 min. The results of this study indicate that a single bout of heavy anaerobic exercise may induce significant hemorheological deterioration lasting for up to 12 h and thus suggest the need to consider such effects in individuals with impaired cardiovascular function.     

Changes in hematological parameters in free-living pigeons (Columba livia f. urbana) during the breeding cycle

The blood parameters—red blood cell (RBC) count, hematocrit (Ht), hemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC)—were studied for the first time in free ranging pigeons Columba livia f. urbana. The aim of the study was to establish a set of reference values for this ubiquitous urban species and to examine a potential influence of the factors such as sex and phase of the breeding cycle on the hematological parameters. Blood was sampled from the adult individuals of both sexes during the breeding cycle. Significant variations in Ht and Hb were observed, while RBC count remained unchanged. The lower hematocrit value and hemoglobin concentration found in both males and females during molt probably resulted from the increase of plasma volume not accompanied by an increase in RBC. On the other hand, a significant physiological stress of nutritional deficiency during this energy-consuming stage may manifest itself in the decreased Ht and Hb values. The higher values of Ht and Hb during the laying phase could be related to the dehydration status. There were no overall differences in MCV, MCH, and MCHC values in either of the breeding stage. A lack of sex dimorphism in the measured and calculated blood parameters was apparent. Data collected herein contribute to the better understanding of general physiology of the ubiquitous urban species. The knowledge of variation in the blood indexes with respect to sex and breeding stage is crucial before blood parameters can provide an useful information on physical condition of the bird.     

Assessment of the hemorheological profile of koala and echidna

Koala, a marsupial, and echidna, a monotreme, are mammals native to Australia. Blood viscosity (62.5–1250 s^?1), red blood cell (RBC) deformability, RBC aggregation, aggregability and surface charge, and hematological parameters were measured in blood samples from six koalas and six echidnas and compared to adult human blood. Koala had the largest RBC mean cell volume (107.7±2.6 fl) compared to echidna (81.3±2.6 fl) and humans (88.4±1.2 fl). Echidna blood exhibited the highest viscosity over the entire range of shear rates. Echidna RBC were significantly less deformable than koala RBC but more deformable than human RBC. Echidna RBC had significantly lower aggregability (i.e., aggregation in standardized dextran medium) than koala or human RBC, while aggregation in autologous plasma was similar for the three species. Erythrocyte surface charge as indexed by RBC electrophoretic mobility was similar for human and echidna cells but was 40% lower for koala RBC. Data obtained during this preliminary study indicate that koala and echidna have distinct hemorheological characteristics; investigation of these properties may reveal patterns relevant to specific behavioral and physiological features of these animals.     

Biochemical and hemato-immunological parameters in juvenile beluga (Huso huso) following the diet supplemented with nettle (Urtica dioica)

The present study investigated the effects of different dietary nettle (Urtica dioica) levels on biochemical, hematological and immunological parameters in beluga (Huso huso). Fish were divided into 4 groups before being fed for 8 weeks with 0%, 3%, 6% and 12% of nettle. The blood samples were collected on week 4 and 8. The use of nettle did not significantly change the mean cell volume, mean cell haemoglobin, lymphocytes, eosinophils, albumin, glucose, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and lysozyme activity on week 4 and 8. After 4 weeks, the total red blood cell (RBC) and hematocrit (Ht) showed a significant increase in 12% nettle group compared to the 3% nettle and control groups but haemoglobin (Hb) had a significant change in 12% nettle compared to the control. At the same time was not found a significant change in the mean cell haemoglobin concentration (MCHC), total white blood cell (WBC), neutrophils, respiratory burst activity (RB), total immunoglobulin (Ig) and total protein (TP), triglyceride (Tri) and cholesterol (Chol). After 8 weeks, the fish treated with nettle exhibited significantly increase in neutrophil and Hb levels compared to the control and between treatment groups, 12% nettle group shown the highest Hb while RBC and Hct values significantly rose in fish fed by 12% compared to the control. Supplementing 6% and 12% nettle increased the WBC and MCHC compared to the other groups. The group fed 12% showed a highly significant difference in RB, TP and Ig after 8 weeks. However, Tri and Chol were significantly decreased in the juvenile beluga fed by the 6% and 12% nettle diet compared to the other groups. The results suggest that by using this herb there will be an improvement in hemato-biochemical parameters and immune function of juvenile beluga.     

Generation of N-ethyl-N-nitrosourea-induced mouse mutants with deviations in hematological parameters

Research on hematological disorders relies on suitable animal models. We retrospectively evaluated the use of the hematological parameters hematocrit (HCT), hemoglobin (HGB), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), red blood cell count (RBC), white blood cell count (WBC), and platelet count (PLT) in the phenotype-driven Munich N-ethyl-N-nitrosourea (ENU) mouse mutagenesis project as parameters for the generation of novel animal models for human diseases. The analysis was carried out on more than 16,000 G1 and G3 offspring of chemically mutagenized inbred C3H mice to detect dominant and recessive mutations leading to deviations in the levels of the chosen parameters. Identification of animals exhibiting altered values and transmission of the phenotypic deviations to the subsequent generations led to the successful establishment of mutant lines for the parameters MCV, RBC, and PLT. Analysis of the causative mutation was started in selected lines, thereby revealing a novel mutation in the transferrin receptor gene (Tfrc) in one line. Thus, novel phenotype-driven mouse models were established to analyze the genetic components of hematological disorders.     

Electrophoretic mobility of human red blood cells coated with poly(ethylene glycol)

Poly(ethylene glycol), abbreviated as PEG, was covalently attached to the surface of human red blood cells (RBC) and the effects of such coating on the regions near the cell's glycocalyx were explored by means of cell electrophoresis. RBC electrophoretic mobilities were measured, in polymer-free buffers of various ionic strengths, as functions of PEG molecular mass (3.35, 18.5, 35.0, 35.9 kDa), geometry, (linear or 8-arm branched) and polymer/RBC ratio during attachment. The results indicate marked decreases of the mobility (up to 85%) which were affected by polymer molecular mass and geometry. Since PEG is neutral and its covalent attachment only removes positively-charged amino groups on the cell membrane, such decreases of mobility likely reflect structural changes near and within the RBC glycocalyx. Experimental results were analyzed using an extended "hairy sphere" model to consider friction and thickness of the polymer layer. Calculated polymer layer thickness increased with molecular mass for linear PEGs and was less extended for a branched PEG of similar molecular mass. Friction within the polymer layer increased with polymer/RBC ratio and for the linear PEGs was inversely related to molecular mass; friction was greatest for the branched PEG. Our results are consistent with the effects of attached PEGs on RBC aggregation and surface antigenic site masking, and suggest the usefulness of electrophoretic mobility techniques for studies of bound neutral polymers.     

Modification of partial pressure of oxygen (P50) in mammalian red blood cells by incorporation of an allosteric effector of hemoglobin

Internalization of inositol hexaphosphate (IHP) in mammalian red blood cells (RBC) produces a modification of the hemoglobin-oxygen affinity, leading to a rightward shift of the dissociation curve. The process of incorporation, based on an osmotic shock, has been tested on RBC of different species. Two dialysis protocols have been defined to transform RBC, the first one for small volumes in a cellulose bag and the other for larger volumes using a commercially available dialysis device. Different optimal conditions must be used for each species. Most of the cellular characteristics of the transformed RBC having encapsulated IHP are similar to those of native cells. For several species, such modified RBC could be reinfused and used for physiological studies.     

Stored red blood cells: A changing universe waiting for its map(s)

The availability of stored red blood cells (RBCs) for transfusion remains an important aspect of the treatment of polytrauma, acute anemia or major bleedings. RBCs are prepared by blood banks from whole blood donations and stored in the cold in additive solutions for typically six weeks. These far from physiological storage conditions result in the so-called red cell storage lesion that is of importance both to blood bankers and to clinical practitioners. Here we review the current state of knowledge about the red cell storage lesion from a proteomic perspective. In particular, we describe the current models accounting for RBC aging and response to lethal stresses, review the published proteomic studies carried out to uncover the molecular basis of the RBC storage lesion, and conclude by suggesting a few possible proteomic studies that would provide further knowledge of the molecular alterations carried by RBCs stored in the cold for six weeks.     

Changes in inflammatory activity,heart rate variability,and biochemical indices in young athletes during the annual training cycle

Inflammatory activity, heart rate variability (HRV), and biochemical and functional indices were assessed in young ski racers during the preparation, competition, and recovery periods of an annual training cycle. During the preparation period, autohemodilution (decreased red blood cell count (RBC) and hematocrit (Ht) levels) and a decrease in the systemic inflammatory activity (C-reactive protein) occurred, without significant differences in the HRV or serum protein and lipid profile. During the competition period, the systemic inflammatory activity increased by 50% (p = 0.047), eliminating differences from the control group, and the HRV indices (SDNN, HF, TP, and IT) decreased (p ≤ 0.013), indicating an increase in the sympathetic effects on the HRV. During the recovery period, hematological indices (Ht and RBC), inflammatory activity, and fibrinogen levels decreased, and the parasympathetic effects on the heart increased. These findings allowed us to conclude that mental and physical activation led to a moderate increase in the systemic inflammatory activity and a shift in the sympathovagal balance towards increased sympathetic activity, providing a nonspecific contribution to the physiological regulation of biochemical (lipoproteins and immunoglobulins) and hematological indices in the athletes. However, similar changes in many biochemical and hematological indices in both groups during the year indicated the important role of a common, probably seasonal, factor in the regulation.     

Estimating physical splenic filtration of Plasmodium falciparum‐infected red blood cells in malaria patients

Splenic filtration of Plasmodium falciparum‐infected red blood cells has been hypothesized to influence malaria pathogenesis. We have developed a minimum cylindrical diameter (MCD) filtration model which estimates physical splenic filtration during malaria infection. The key parameter in the model is the MCD, the smallest tube or cylinder that a red blood cell (RBC) can traverse without lysing. The MCD is defined by a relationship between the RBC surface area and volume. In the MCD filtration model, the MCD filtration function represents the probability of a cell becoming physically removed from circulation. This modelling approach was implemented at a field site in Blantyre, Malawi. We analysed peripheral blood samples from 120 study participants in four clinically defined groups (30 subjects each): cerebral malaria, uncomplicated malaria, aparasitaemic coma and healthy controls. We found statistically significant differences in the surface area and volumes of uninfected RBCs when healthy controls were compared with malaria patients. The estimated filtration rates generated by the MCD model corresponded to previous observations in ex vivo spleen experiments and models of red blood cell loss during acute malaria anaemia.There were no differences in the estimated splenic filtration rates between cerebral malaria and uncomplicated malaria patients. The MCD filtration model estimates that at time of admission, one ring‐stage infected RBC is physically filtered by the spleen for each parasite that remains in peripheral circulation. This field study is the first to use microfluidic devices to identify rheological diversity in RBC populations associated with malaria infection and illness in well‐characterized groups of children living in a malaria endemic area.     

Simulation of a Single Red Blood Cell Flowing Through a Microvessel Stenosis Using Dissipative Particle Dynamics

The motion and deformation of a single red blood cell flowing through a microvessel stenosis was investigated employing dissipative particle dynamics (DPD) method. The numerical model considers plasma, cytoplasm, the RBC membrane and the microvessel walls, in which a three dimensional coarse-grained spring network model of RBC’s membrane was used to simulate the deformation of the RBC. The suspending plasma was modelled as an incompressible Newtonian fluid and the vessel walls were regarded as rigid body. The body force exerted on the free DPD particles was used to drive the flow. A modified bounce-back boundary condition was enforced on the membrane to guarantee the impenetrability. Adhesion of the cell to the stenosis vessel surface was mediated by the interactions between receptors and ligands. Firstly, the motion of a single RBC in a microfluidic channel was simulated and the results were found in agreement with the experimental data cited by [1]. Then the mechanical behavior of the RBC in the microvessel stenosis was studied. The effects of the bending rigidity of membrane, the size of the stenosis and the driven body force on the deformation and motion of red blood cell were discussed.     

Therapeutic effect of chloroquine(CQ)-containing immunoliposomes in rats infected with Plasmodium berghei parasitized mouse red blood cells: comparison with combinations of antibodies and CQ or liposomal CQ

The potential therapeutic application of chloroquine-containing immunoliposomes (Fab'-lipCQ) in a Plasmodium berghei malaria model was studied. Extending a previously described in vivo model (Peeters et al. (1988) Biochim. Biophys. Acta 943, 137-147) it was demonstrated that injection of antimouse red blood cell (anti-mRBC) Fab'-lipCQ was significantly more effective than liposome-encapsulated chloroquine (lipCQ) or free chloroquine in delaying or preventing a patent infection after intravenous injection of parasitized mouse red blood cells (p-mRBC) in rats. The results could be improved by injecting synchronized infected cells instead of non-synchronous p-mRBC in order to minimize the presence of free parasites which could easily infect rat RBC. It was further demonstrated that sequential injection of anti-mRBC IgG and lipCQ or chloroquine resulted in complete inactivation of the injected parasitized cells while Fab'-lipCQ administration resulted in a maximum score of 50% at an equal chloroquine, protein and phospholipid dose. In this report the potential of the concept of drug targeting for the effective treatment of a disease, which manifests in blood cells, was demonstrated.     

Association between the ABO locus and hematological traits in Korean

ABSTRACT: BACKGROUND: Recently, genomewide association studies identified a pleiotropic gene locus, ABO, as being significantly associated with hematological traits. To confirm the effects of ABO on hematological traits, we examined the link between the ABO locus and hematological traits in Korean population-based cohorts. RESULTS: Six tagging SNPs for ABO were analyzed with regard to their effects on hematological traits [white blood cell count (WBC), red blood cell count (RBC), platelet (Plat), mean corpuscular volume (MCV), and mean corpuscular haemoglobin concentration (MCHC)]. Linear regression analyses were performed, controlling for recruitment center, sex, and age as covariates. Of the 6 tagging SNPs, 3 (rs2073823, rs8176720, and rs495828) and 3 (rs2073823, rs8176717, and rs687289) were significantly associated with RBC and MCV, respectively (Bonferroni correction p-value criteria < 0.05/6 = 0.008). rs2073823 and a reported SNP (rs8176746), as well as rs495828 and a reported SNP (rs651007), showed perfect linkage disequilibrium status (r2s = 0.99). Of the remaining 3 SNPs (rs8176720, rs8176717 and rs687289), rs8176717 generated an independent signal with moderate p-value (= 0.045) when it was adjusted for by rs2073823 (the most significant SNP). We also identified a copy number variation (CNV) that was tagged by the SNP rs8176717, the minor allele of which correlated with the deletion allele of CNV. Our haplotype analysis indicated that the haplotype that contained the CNV deletion was significantly associated with MCV (beta +/- se = 0.363 +/- 0.118, p =2.09 x 10-3). CONCLUSIONS: Our findings confirm that ABO is one of the genetic factors that are associated with hematological traits in the Korean population. This result is notable, because GWASs fail to evaluate the link between a CNV and phenotype traits.     

High affinity interactions between red blood cell receptors and synthetic Plasmodium thrombospondin-related apical merozoite protein (PTRAMP) peptides

Plasmodium falciparum thrombospondin-related apical merozoite protein (PTRAMP) has a thrombospondin related (TSR) domain which in many proteins has been reported as a fragment involved in pathogen-host and cell-interactions. Receptor-ligand studies using eighteen non-overlapping 20-aminoacid-long synthetic peptides from this protein were carried out to determine regions involved in parasite invasion of red blood cells (RBC). Two high activity binding peptides (HABPs) were determined, 33405 (21YISSNDLTSTNLKVRNNWEH40) and 33413 (180LEGPIQFSLGKSSGAFRINY199), presenting high dissociation constants and positive cooperativity. One of the HABPs displayed a modified Plasmodium export element (PEXEL), suggesting that this protein could be involved in the merozoite cytoplasmic reticulum, parasitophorous vacuole, red blood cell (RBC) cytosol, and probably infected RBC (iRBC) membrane transport of some other molecules and nutrients. Enzymatic treatment of RBCs increased HABP 33405 binding to them whilst it decreased HABP 33413 binding. Merozoite invasion assays revealed that HABPs have around 57% ability to inhibit new RBC invasion. Circular dichroism revealed the presence of possible alpha-helical elements in both HABPs structures. RBC binding interaction specificity and the presence of a PEXEL motif make these 2 HABPs good candidates for being included in further studies to develop a new multi-antigenic, multi-stage, subunit-based, chemically-synthesised, anti-malarial vaccine.     

Effects of capture on biological parameters in free-ranging bighorn sheep (Ovis canadensis): evaluation of drop-net, drive-net, chemical immobilization and the net-gun

Blood samples and physiological data were collected from 634 bighorn sheep captured between 1980 and 1986 in the western United States. Bighorn sheep were evaluated for physiological parameters (temperature, pulse and respiration), selected biochemical parameters (cortisol, creatine phosphokinase (CPK), serum glutamic oxaloacetic transaminase (SGOT), lactic dehydrogenase (LDH), alkaline phosphotase (AP), potassium, sodium, chloride, creatinine, blood urea nitrogen (BUN), selenium, glucose, total protein, plasma pH and plasma PCO2), and selected hematological parameters (packed cell volume (PCV), hemoglobin (HB), red blood cell count (RBC), and white blood cell count (WBC]. These parameters were compared among bighorn sheep captured by four different methods: drop-net (n = 158), drive-net (n = 249), chemical immobilization (n = 90) and the net-gun (n = 137). Biological parameters affected by stress, including temperature, respiration, cortisol, CPK, SGOT, potassium, glucose and WBC revealed significant differences among capture methods (P less than 0.05). Some blood parameter differences, including temperature, respiration, cortisol, glucose and WBC could be explained partially by the distribution of age and sex within capture method groups. Drop-net and net-gun methods of capture appeared to produce the least amount of alteration to biological parameters related to capture stress or compromise and capture mortality. Drive-net was similar to the former methods while chemical immobilization caused the greatest changes in the above physiological, biochemical and hematological parameters.     

Genome-wide association study of porcine hematological parameters in a Large White × Minzhu F2 resource population

Hematological traits, which are important indicators of immune function in animals, have been commonly examined as biomarkers of disease and disease severity in humans and animals. Genome-wide significant quantitative trait loci (QTLs) provide important information for use in breeding programs of animals such as pigs. QTLs for hematological parameters (hematological traits) have been detected in pig chromosomes, although these are often mapped by linkage analysis to large intervals making identification of the underlying mutation problematic. Single nucleotide polymorphisms (SNPs) are the common form of genetic variation among individuals and are thought to account for the majority of inherited traits. In this study, a genome-wide association study (GWAS) was performed to detect regions of association with hematological traits in a three-generation resource population produced by intercrossing Large White boars and Minzhu sows during the period from 2007 to 2011. Illumina PorcineSNP60 BeadChip technology was used to genotype each animal and seven hematological parameters were measured (hematocrit (HCT), hemoglobin (HGB), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), red blood cell count (RBC) and red blood cell volume distribution width (RDW)). Data were analyzed in a three step Genome-wide Rapid Association using the Mixed Model and Regression-Genomic Control (GRAMMAR-GC) method. A total of 62 genome-wide significant and three chromosome-wide significant SNPs associated with hematological parameters were detected in this GWAS. Seven and five SNPs were associated with HCT and HGB, respectively. These SNPs were all located within the region of 34.6-36.5 Mb on SSC7. Four SNPs within the region of 43.7-47.0 Mb and fifty-five SNPs within the region of 42.2-73.8 Mb on SSC8 showed significant association with MCH and MCV, respectively. At chromosome-wide significant level, one SNP at 29.2 Mb on SSC1 and two SNPs within the region of 26.0-26.2 Mb were found to be significantly associated with RBC and RDW, respectively. Many of the SNPs were located within previously reported QTL regions and appeared to narrow down the regions compared with previously described QTL intervals. In current research, a total of seven significant SNPs were found within six candidate genes SCUBE3, KDR, TDO, IGFBP7, ADAMTS3 and AFP. In addition, the KIT gene, which has been previously reported to relate to hematological parameters, was located within the region significantly associated with MCH and MCV and could be a candidate gene. These results of this study may lead to a better understanding of the molecular mechanisms of hematological parameters in pigs.