Oxygen-carrying Capacity Of Blood Research Articles

On the mechanisms of stress-induced human spleen contraction: training for a higher blood oxygen-carrying capacity.

Despite its comparatively limited size in humans, spleen has been shown able to expel red-blood cells in the circulation and thus augment blood oxygen-carrying capacity under certain physiologic conditions. In the present state-of-the-art review, the short- and long-term regulation of spleen volume will be discussed. With regards to the physiological mechanism underlying spleen contraction, sympathetic activation stands as the prime contributor to the response. A dose-dependent relationship between specific interventions of apnea, exercise and hypoxia (imposed separately or in combination) and spleen contraction alleges to the trainability of the spleen organ. The trainability of the spleen is further substantiated by virtue of cross-sectional and longitudinal studies reporting robust increases in both organ volume at rest and subsequent spleen contraction. Alternative ways to assess the relationship between hematologic gains and the magnitude of spleen contraction (i.e., the reduction of spleen volume) will be presented herein. In extension of changes in the conventional measures of hemoglobin concentration and hematocrit, assessment of hemoglobin mass and total blood volume using the (safe, low-cost and time-efficient) CO-rebreathing technique could deepen scientific knowledge on the efficiency of human spleen contraction.

The mediating effect of blood biomarkers in the associations between inflammatory bowel disease and incident psychiatric disorders: a prospective cohort study.

Despite the growing evidence of an association between inflammatory bowel disease (IBD) and psychiatric disorders, there has been limited research exploring the underlying mediating role of blood biomarkers on the gut-brain axis. This study aimed to examine the association between IBD and the risk of incident psychiatric disorders and investigate whether and how blood biomarkers mediate this association. This prospective cohort study using data from the UK Biobank included participants without psychiatric diagnoses at baseline. The case cohort consisted of participants with a hospital-based diagnosis of IBD at baseline. The primary outcome was all psychiatric disorders. Secondary outcomes included 11 major psychiatric disorders. Cox regression models estimated adjusted hazard ratios (HRs) for psychiatric outcomes. Causal mediation models investigated the potential mediation effects of blood biomarkers. Among 491,131 participants, patients with IBD exhibited higher risks of overall psychiatric disorders (HR 1.23 [95% CI 1.13-1.33]), substance misuse (1.23 [1.09-1.38]), depression (1.36 [1.22-1.52]), anxiety (1.15 [1.01-1.30]) and post-traumatic stress disorder (1.87 [1.00-3.51]) compared with non-IBD participants. The association with incident substance misuse was only among patients with Crohn's disease (CD, 1.47 [1.23-1.76]), but not ulcerative colitis (UC, 1.01 [0.84-1.21]). Mediation analysis revealed 16, 14, 15, and 6 biomarkers partially mediated the associations for all psychiatric disorders, substance misuse, depression, and anxiety, respectively. Six blood markers showed the strongest mediating effects: neutrophil count (12.04%), C-reactive protein (10.29%), systemic immune-inflammatory index (8.94%), erythrocyte distribution width (16.51%), erythrocyte count (9.76%), and albumin (9.15%). Moreover, several blood mediators of CD identified in association with incident substance misuse may explain the risk discrepancy between IBD subtype. The blood biomarkers of inflammation, blood oxygen-carrying capacity, and metabolism mediate the effect of IBD on the risk of psychiatric outcomes and could be considered as a therapeutic target.

Coping with environmental degradation: Physiological and morphological adjustments of wild mangrove fish to decades of aquaculture-induced nutrient enrichment

The impact of eutrophication on wild fish individuals is rarely reported. We compared physiological and morphological traits of Siganus lineatus chronically exposed to aquaculture-induced eutrophication in the wild with individuals living at a control site. Eutrophication at the impacted site was confirmed by elevated organic matter (up to 150 % higher), phytoplankton (up to 7 times higher), and reduced oxygen (up to 60 % lower). Physiological and morphological traits of S. lineatus differed significantly between the two sites. Fish from the impacted site exhibited elevated hypoxia tolerance, increased gill surface area, shorter oxygen diffusion distances, and altered blood oxygen-carrying capacity. Elevated blood lactate and scope for anaerobic ATP production were observed, suggesting enhanced survival below critical oxygen levels. A significant 8.5 % increase in metabolic costs and altered allometric scaling, related to environmental degradation, were recorded. Our study underscores eutrophication's profound impact at the organism-level and the importance to mitigate it.

Bilateral Hearing Loss after Carbon Monoxide Poisoning

Background: Carbon monoxide (CO) is an odorless, colorless, flammable gas that is formed by the incomplete combustion of fuels and binds to hemoglobin with 200 to 250 times greater affinity compared to oxygen. As a result, blood oxygen-carrying capacity is reduced when CO is bound to hemoglobin. Reversible and irreversible unilateral or bilateral hearing loss due to CO poisoning has rarely been reported. We present a case of an 18-year-old previously healthy male with bilateral hearing loss after severe CO poisoning. Case Report: An 18-year-old male with no past medical history presented to the emergency department (ED) after being found unconscious with emesis in his vehicle. He failed to respond to Naloxone. In the ED, he was obtunded with vital signs significant only for tachycardia of 115 bpm. Initial workup revealed leukocytosis (WBC 16.0 10*3/uL), hyperglycemia (glucose 195 mg/dl ) and high sensitivity troponin elevation (131 ng/L). Electrocardiogram revealed sinus tachycardia with an incomplete right bundle branch block. Head CT and urine drug immunoassay were negative. Several hours after ED arrival, it was reported that the vehicle had a known problem with the exhaust pipe. The patient remained unresponsive for several hours. Approximately 6 hours after ED arrival, a carboxyhemoglobin level was ordered and returned at 9.5%. A non-rebreather oxygen mask was applied and the patient began waking up shortly after. Prior to receiving the first session of hyperbaric oxygen therapy (HBO2), the patient complained of bilateral hearing loss with tinnitus. Three sessions of HBO2 were done in the first 24 hours. The patient remained with bilateral hearing loss and tinnitus with minimal improvement over the three day hospitalization. A 3 day course of dexamethasone 10 mg daily was given. Audiological testing was not performed prior to discharge. Six months after discharge, he continued to have tinnitus and hearing loss though endorsed improvement. His audiogram shows moderate hearing loss. Discussion: CO poisoning is a rare cause of hearing loss. Tinnitus with hearing loss is reported even less. The mechanism for hearing loss in the setting of CO poisoning has not been identified however it is believed to be due to tissue hypoxia. The pattern of hearing loss after acute or chronic CO poisoning is typically sensorineural and could be unilateral or bilateral, reversible or irreversible. HBO2 is commonly used to treat severe CO poisoning, and occasionally to treat idiopathic sensorineural hearing loss (ISNHL). However, HBO2 has not been described for the sole purpose of treating CO-associated hearing loss. Corticosteroids have been shown to prevent delayed neuropsychiatric sequelae after CO poisoning and to treat ISNHL, but no reported cases with CO hearing loss. Due to the potential benefits of these relatively benign interventions, the patient was treated with HBO2 and corticosteroids with improvement in symptoms. Conclusion: Hearing loss is a rare clinical manifestation of carbon monoxide poisoning with few reported cases in the literature. Resulting hearing loss may be unilateral or bilateral, and reversible or irreversible.

Impaired O2 unloading from stored blood results in diffusion-limited O2 release at tissues: evidence from human kidneys

AbstractThe volume of oxygen drawn from systemic capillaries down a partial pressure gradient is determined by the oxygen content of red blood cells (RBCs) and their oxygen-unloading kinetics, although the latter is assumed to be rapid and, therefore, not a meaningful factor. Under this paradigm, oxygen transfer to tissues is perfusion-limited. Consequently, clinical treatments to optimize oxygen delivery aim at improving blood flow and arterial oxygen content, rather than RBC oxygen handling. Although the oxygen-carrying capacity of blood is increased with transfusion, studies have shown that stored blood undergoes kinetic attrition of oxygen release, which may compromise overall oxygen delivery to tissues by causing transport to become diffusion-limited. We sought evidence for diffusion-limited oxygen release in viable human kidneys, normothermically perfused with stored blood. In a cohort of kidneys that went on to be transplanted, renal respiration correlated inversely with the time-constant of oxygen unloading from RBCs used for perfusion. Furthermore, the renal respiratory rate did not correlate with arterial O2 delivery unless this factored the rate of oxygen-release from RBCs, as expected from diffusion-limited transport. To test for a rescue effect, perfusion of kidneys deemed unsuitable for transplantation was alternated between stored and rejuvenated RBCs of the same donation. This experiment controlled oxygen-unloading, without intervening ischemia, holding all non-RBC parameters constant. Rejuvenated oxygen-unloading kinetics improved the kidney’s oxygen diffusion capacity and increased cortical oxygen partial pressure by 60%. Thus, oxygen delivery to tissues can become diffusion-limited during perfusion with stored blood, which has implications in scenarios, such as ex vivo organ perfusion, major hemorrhage, and pediatric transfusion. This trial was registered at www.clinicaltrials.gov as #ISRCTN13292277.

Effect of tarpaulin pond on the growth and haematology of catfish (Clarias gariepinus)

The present comparative study investigated the haematological and growth parameters of catfish reared in both earthen and tarpaulin ponds. The growth response of the fish in both ponds such as overall weight gain, production index, survival rate, daily weight gain and length gain in the fish samples were determined. The overall weight gain in the catfish grown in earthen pond was higher (800 – 1000 g) than those from tarpaulin ponds (600 – 800 g). The production index of fish from earthen pond was higher than those of tarpaulin pond. The survival rate was higher in earthen pond (100%) than tarpaulin pond (80%). Moreover, daily weight gain and length gain were higher in earthen pond (12.50 g and 50 cm) than tarpaulin pond (10.00 g and 30 cm) respectively. Also, the haematological parameters such as the packed cell volume (PCV), haemoglobin concentration (HB), Red Blood Cell (RBC), White Blood Cell (WBC) count and other blood parameters of each of the blood sample, were determined using 5-part differential Haematology Auto-analyzer (Mindray BC 5300 model).Catfish from earthen pond recorded the highest haemoglobin value (8.68±0.15 g/dL) than that of tarpaulin pond (7.78±0.03g/dL) this means that the oxygen carrying capacity of blood of catfish from earthen pond is higher than those of tarpaulin pond. Packed cell volume (PCV) value was recorded the highest in earthen pond (25.00%) again than that of tarpaulin pond (23.50%). Earthen pond recorded the least white blood cell (WBC) count (5268.30±54.03 x 103/L) compared to that of tarpaulin pond (6170.50±37.09 x 103/L). Red blood cell (RBC) count was recorded the highest in earthen pond (2.74±0.01 x 106/L) than that of tarpaulin pond (2.18±0.01x 106/L). Blood of catfish from tarpaulin pond recorded the highest neutrophils (60%) than that of earthen pond (53%). Earthen pond recorded the highest leucocytes (40%) than that of tarpaulin pond (37%). Also, monocytes counts are higher in earthen pond (7%) than tarpaulin pond (3%). In conclusion, the results of the present study indicated that the type of pond material used to rear fish can alter growth and haematological parameters.

Nickel chloride generates cytotoxic ROS that cause oxidative damage in human erythrocytes

BackgroundNickel is a heavy metal that is regarded as a possible hazard to living organisms due to its toxicity and carcinogenicity. Nickel chloride (NiCl2), an inorganic divalent Ni compound, has been shown to cause oxidative stress in cells by altering the redox equilibrium. We have investigated the effect of NiCl2 on isolated human erythrocytes under in vitro condition. MethodsIsolated erythrocytes were treated with different concentrations of NiCl2 (25–500 µM) for 24 h at 37 ºC. Hemolysates were prepared and several biochemical parameters were analyzed in them. ResultsTreatment of erythrocytes with NiCl2 enhanced the intracellular generation of reactive oxygen species (ROS). A significant increase in hydrogen peroxide levels and oxidation of proteins and lipids was also seen. This was accompanied by a reduction in levels of nitric oxide, glutathione, free amino groups and total sulfhydryl groups. NiCl2 treatment impaired both enzymatic and non-enzymatic defense systems, resulting in lowered antioxidant capacity and diminished ability of cells to quench free radicals and reduce metal ions. NiCl2 exposure also had an inhibitory effect on the activity of enzymes involved in pathways of glucose metabolism (glycolytic and pentose phosphate shunt pathways). Increased level of methemoglobin, which is inactive in oxygen transport, was also seen. The rate of heme breakdown increased resulting in the release of free iron. Exposure to NiCl2 led to considerable cell lysis, indicating damage to the erythrocyte membrane. This was supported by the inhibition of membrane bound enzymes and increase in the osmotic fragility of NiCl2 treated cells. NiCl2 treatment caused severe morphological alterations with the conversion of normal discocytes to echinocytes. All changes were seen in a NiCl2 concentration-dependent manner. ConclusionNiCl2 generates cytotoxic ROS in human erythrocytes which cause oxidative damage that can decrease the oxygen carrying capacity of blood and also lead to anemia.

Settleable atmospheric particulate matter affects the swimming performance and aerobic metabolic rate of Nile tilapia (Oreochromis niloticus)

Atmospheric particulate matter (APM) produced by the steel industry comprises a complex mixture of particles that includes a wide variety of metals and metallic nanoparticles. These particles settle out onto areas surrounding the industries. There is evidence that this ‘settleable’ APM (SePM) may cause air-to-water cross-contamination with significant effects on aquatic biota. Recent investigations have reported sublethal impacts on the gill structure and blood oxygen-carrying capacity of fishes, which raises the hypothesis that there will be consequences for gas exchange capacity and ability to support aerobic activities. Therefore, we investigated the effects of an environmentally relevant level of SePM contamination on swimming performance and associated aerobic metabolic rates in Nile tilapia, Oreochromis niloticus. Short-term exposure (96 h) to SePM reduced critical swimming speed, energetic efficiency of aerobic swimming, standard metabolic rate, maximum metabolic rate, and aerobic scope. The compromised swimming performance could have adverse ecological effects by limiting foraging ability, predator evasion, territorial protection, and migration. The impairments to aerobic capacity could also affect overall fish performance by influencing long-term energy balance and allocation to growth and reproduction. Thus, despite being sublethal, SePM contamination is considerably debilitating, and if its limiting effects are not compensated for in the longer term, this may reduce the survival and fitness of fish populations.

Acute Chest Syndrome in Sickle Cell Disease.

Acute chest syndrome (ACS) is the leading cause of mortality among individuals with sickle cell disease (SCD) accounting for 25% of all deaths. The etiologies and clinical manifestations of ACS are variable among children and adults, with a lack of clear risk stratification guidelines for the practicing clinician. In addition, the management of ACS is based on limited evidence and is currently guided primarily by expert opinion. This manuscript reviews the pathophysiology, risk factors, and current management strategies for ACS through a review of published data on this subject between 1988 and 2022. Blood transfusion is often used as a therapeutic intervention for ACS to increase blood's oxygen-carrying capacity and reduce complications by reducing hemoglobin S (HbS) percentage, based on the very low quality of the evidence about its efficacy. The benefit of RBC transfusion for ACS has been described in case series and observational studies, but randomized studies comparing simple transfusion vs. exchange transfusions for ACS are lacking. In this review, we conclude that the development of clinical and laboratory risk stratification is necessary to further study an optimal management strategy for individuals with ACS to avoid transfusion-related complications while minimizing mortality.

Experimental reduction in blood oxygen-carrying capacity alters foraging behaviour in a colonial waterbird.

Oxidative metabolism is a key component of organismal physiology and it is primarily determined by aerobic capacity, which depends on the capacity of blood to carry oxygen. However, experimental manipulations of blood oxygen-carrying capacity are scarcely implemented to test ecophysiological hypotheses in vertebrate populations. Here we combined an experimental manipulation of blood oxygen-carrying capacity with GPS-tracking to test if suboptimal (reduced) haematological performance affects foraging behaviour in a colonial waterbird, the black-headed gull Chroicocephalus ridibundus. First, a validation of phenylhydrazine (PHZ) treatment in gulls revealed 9-18% reduction in haematocrit and blood haemoglobin concentration (via oxidative denaturation and haemolysis of erythrocytes). Then, GPS-tracking of experimental (PHZ-treated) and control (saline-treated) gulls during the incubation period provided no support for reduced or suspended engagement in energetically costly activities (long-distance foraging trips) by experimental birds. Instead, we found evidence for fine-scale alterations in foraging behaviour of PHZ-treated individuals, which resulted in fewer foraging trips per unit time, but trips that were longer in duration and in distance compared to control birds. This suggests reduced foraging performance of experimental birds (e.g. lower capacity to find and collect food during trips) or evasion of social competition, although no differences in the total investment in foraging may also suggest compensatory physiological responses to haemolytic anaemia. Our study contributes to better understanding of physio-ecological nexus in non-diving colonial avian species. At the same time, it should be subject to further investigation, if behavioural effects of reduced aerobic capacity may have any implications for gull condition and reproductive performance.

Comparative evaluation of hemoglobin, erythrocyte sedimentation rate, and differential leukocyte count

Background: Anemia is defined as the deficiency in the oxygen-carrying capacity of blood either due to reduced hemoglobin %(Hb%) or reduced Red Blood Corpuscles (RBC) count. currently the association of anemia in periodontitis patients and the possible etiology cited for decreased blood counts was the downregulation of erythropoiesis in the bone marrow by proinflammatory cytokines released due to periodontal disease. Aims and Objectives: To evaluate the relation between anemia and periodontitis by estimation of blood parameters and to assess whether periodontitis like other inflammatory conditions can lead to anemia. It is a randomized controlled clinical trial. Materials and Methods: A total of 30 subjects who visited the Department of periodontics, Mahe Institute of dental science and hospitals was included in the study and divided into three groups. A total of 10 healthy controls, 10 chronic generalized gingivitis, and 10 chronic generalized periodontitis patients were selected among the Kerala population. Hemoglobin levels (Hb), erythrocyte sedimentation rate (ESR), Differential leukocyte count, gingival index, OHIS index, and probing depth were recorded. Results: The results revealed a decrease in Hb and erythrocyte counts and an increase in white blood corpuscle counts in chronic generalized periodontitis compared to healthy controls and chronic generalized gingivitis group. Conclusions: The treatment of periodontitis can improve hematocrit and other related blood parameters in chronic generalized periodontitis patients with anemia. This provides evidence that periodontitis like other chronic diseases may also cause anemia.

Blood Variation Implicates Respiratory Limits on Elevational Ranges of Andean Birds.

AbstractThe extent to which species ranges reflect intrinsic physiological tolerances is a major question in evolutionary ecology. To date, consensus has been hindered by the limited tractability of experimental approaches across most of the tree of life. Here, we apply a macrophysiological approach to understand how hematological traits related to oxygen transport shape elevational ranges in a tropical biodiversity hot spot. Along Andean elevational gradients, we measured traits that affect blood oxygen-carrying capacity-total and cellular hemoglobin concentration and hematocrit, the volume percentage of red blood cells-for 2,355 individuals of 136 bird species. We used these data to evaluate the influence of hematological traits on elevational ranges. First, we asked whether the sensitivity of hematological traits to changes in elevation is predictive of elevational range breadth. Second, we asked whether variance in hematological traits changed as a function of distance to the nearest elevational range limit. We found that birds showing greater hematological sensitivity had broader elevational ranges, consistent with the idea that a greater acclimatization capacity facilitates elevational range expansion. We further found reduced variation in hematological traits in birds sampled near their elevational range limits and at high absolute elevations, patterns consistent with intensified natural selection, reduced effective population size, or compensatory changes in other cardiorespiratory traits. Our findings suggest that constraints on hematological sensitivity and local genetic adaptation to oxygen availability promote the evolution of the narrow elevational ranges that underpin tropical montane biodiversity.

Two-stage hemoglobin prediction based on prior causality.

Perioperative hemoglobin (Hb) levels can influence tissue metabolism. For clinical physicians, precise Hb concentration greatly contributes to intraoperative blood transfusion. The reduction in Hb during an operation weakens blood's oxygen-carrying capacity and poses threats to multiple systems and organs of the whole body. Patients can die from perioperative anemia. Thus, a timely and accurate non-invasive prediction for patients' Hb content is of enormous significance. In this study, targeted toward the palpebral conjunctiva images in perioperative patients, a non-invasive model for predicting Hb levels is constructed by means of deep neural semantic segmentation and a convolutional network based on a priori causal knowledge, then an automatic framework was proposed to predict the precise concentration value of Hb. Specifically, according to a priori causal knowledge, the palpebral region was positioned first, and patients' Hb concentration was subjected to regression prediction using a neural network. The model proposed in this study was experimented on using actual medical datasets. The R 2 of the model proposed can reach 0.512, the explained variance score can reach 0.535, and the mean absolute error is 1.521. In this study, we proposed to predict the accurate hemoglobin concentration and finally constructed a model using the deep learning method to predict eyelid Hb of perioperative patients based on the a priori casual knowledge.

Settleable atmospheric particulate matter affects cardiorespiratory responses to hypoxia in Nile tilapia (Oreochromis niloticus)

Atmospheric particulate matter (APM) emitted by iron ore processing industries has a complex composition, including diverse metallic particles and nanoparticles. Settleable APM (SePM) causes air to water cross-contamination and has recently been demonstrated to have harmful sublethal impacts on fish, eliciting stress responses, affecting the immune system, and reducing blood oxygen-carrying capacity. These findings imply potential consequences for fish aerobic performance and energy allocation, particularly in their ability to tolerate respiratory challenges such as aquatic hypoxia. To assess that potential limitation, we analyzed metabolic, cardiorespiratory, and morphological alterations after exposing tilapia, Oreochromis niloticus, to an environmentally relevant concentration of SePM (96 h) and progressive hypoxia. The contamination initiated detectable gill damage, reducing respiratory efficiency, increasing ventilatory effort, and compromising fish capacity to deal with hypoxia. Even in normoxia, the resting respiratory frequency was elevated and limited respiratory adjustments during hypoxia. SePM increased O2crit from 26 to 34% of O2 (1.84 to 2.76 mg O2·L−1). Such ventilatory inefficacy implies higher ventilatory cost with relevant alterations in energy allocation. Progression in gill damage might be problematic and cause: infection, blood loss, ion imbalance, and limited cardiorespiratory performance. The contamination did not cause immediate lethality but may threaten fish populations due to limitations in physiological performance. This was the first investigation to evaluate the physiological responses of fish to hypoxia after SePM contamination. We suggest that the present level of environmental SePM deserves attention. The present results demonstrate the need for comprehensive studies on SePM effects in aquatic fauna.

Anaemia and Antianaemic Medications

Anemia is a group of diseases described by decrease in hemoglobin or red blood cells, resulting in decreased oxygen-carrying capacity of blood. Iron deficiency is the most frequent nutritional deficiency, and the most routine cause of nutrition related anemia. Vitamin B12 deficiency is the sequence of impaired absorption (pernicious anemia are imperfect production of intrinsic factor compulsory for absorption of vitamin B 12). Without folic acid, deoxyribonucleic duplication and cell separation cannot continue. Colchicine, para-aminosalicylic acid and heavy alcohol intake for lengthy than 2 weeks perhaps generates malabsorption of vitamin B12. Iron combines with porphyrin and globin chains to figure hemoglobin, which is underpinning for oxygen release from the lungs to different tissues. Folic acid should not be given alone in patients with pernicioius anemia without knowing whether they also have a Vitamin B12 deficiency.

Ecological and life-history correlates of erythrocyte size and shape in Lepidosauria.

Blood oxygen‐carrying capacity is shaped both by the ambient oxygen availability as well as species‐specific oxygen demand. Erythrocytes are a critical part of oxygen transport and both their size and shape can change in relation to species‐specific life‐history, behavioural or ecological conditions. Here, we test whether components of the environment (altitude), life history (reproductive mode, body temperature) and behaviour (diving, foraging mode) drive erythrocyte size variation in the Lepidosauria (lizards, snakes and rhynchocephalians). We collected data on erythrocyte size (area) and shape (L/W: elongation ratio) from Lepidosauria across the globe (N = 235 species). Our analyses show the importance of oxygen requirements as a driver of erythrocyte size. Smaller erythrocytes were associated with the need for faster delivery (active foragers, high‐altitude species, warmer body temperatures), whereas species with greater oxygen demands (diving species, viviparous species) had larger erythrocytes. Erythrocyte size shows considerable cross‐species variation, with a range of factors linked to the oxygen delivery requirements being major drivers of these differences. A key future aspect for study would include within‐individual plasticity and how changing states, for example, pregnancy, perhaps alter the size and shape of erythrocytes in Lepidosaurs.

Settleable atmospheric particulate matter induces stress and affects the oxygen-carrying capacity and innate immunity in Nile tilapia (Oreochromis niloticus)

Steel industry emissions of atmospheric particulate matter are responsible for air to water cross-contamination, which deposits metal/metalloid contaminants in aquatic ecosystems. This source of contamination has not been considered in most of the environmental monitoring protocols. Settleable atmospheric particulate matter (SePM) collected in an area of steel industry influence was used to analyze the sublethal effects on the hematological and innate immunological variables in Nile tilapia (Oreochromis niloticus) after short-term exposure (96 h). Blood samples were analyzed to evaluate the oxygen-carrying transport capacity, innate immune activity and stress biomarkers after exposure to ecologically relevant concentration of SePM. The exposure reduced blood oxygen-carrying capacity by lessening hematocrit, hemoglobin, erythrocyte, and mean corpuscular hemoglobin concentration. Compensatory increments in mean corpuscular volume and mean corpuscular hemoglobin have also been observed. The contaminant impacted the immune system by reducing the number of leukocytes, thrombocytes, and monocytes, total plasma protein, leukocyte respiratory activity, and by increasing lysozyme concentration. Furthermore, the contaminant caused endocrine stress response, raising plasma cortisol and glucose. Therefore, the alterations caused by SePM threatened the capacity of sustaining aerobic metabolism, impaired the immune system, and changed the energy allocation due to both stress response and immune effect. This may have important implications for the impact of SePM on aquatic ecosystems. Future investigations should assess SePM impact on general physiology and aerobic performance, especially to face common ecological challenges such as hypoxia and sustained swimming. These results point out the need to develop proper protocols to address the air-to-water cross-contamination risks by iron ore processing industries.

Differences in Cardiac Output and Aerobic Capacity Between Sexes Are Explained by Blood Volume and Oxygen Carrying Capacity.

Whether average sex differences in cardiorespiratory fitness can be mainly explained by blood inequalities in the healthy circulatory system remains unresolved. This study evaluated the contribution of blood volume (BV) and oxygen (O2) carrying capacity to the sex gap in cardiac and aerobic capacities in healthy young individuals. Healthy young women and men (n = 28, age range = 20–43 years) were matched by age and physical activity. Echocardiography, blood pressures, and O2 uptake were measured during incremental exercise. Left ventricular end-diastolic volume (LVEDV), stroke volume (SV), cardiac output (Q), peak O2 uptake (VO2peak), and BV were assessed with precise methods. The test was repeated in men after blood withdrawal and reduction of O2 carrying capacity, reaching women’s levels. Before blood normalization, exercise cardiac volumes and output (LVEDV, SV, Q) adjusted by body size and VO2peak (42 ± 9 vs. 50 ± 11 ml⋅min–1⋅kg–1, P < 0.05) were lower in women relative to men. Blood normalization abolished sex differences in cardiac volumes and output during exercise (P ≥ 0.100). Likewise, VO2peak was similar between women and men after blood normalization (42 ± 9 vs. 40 ± 8 ml⋅min–1⋅kg–1, P = 0.416). In conclusion, sex differences in cardiac output and aerobic capacity are not present in experimental conditions matching BV and O2 carrying capacity between healthy young women and men.

Oxygen consumption and acid secretion in isolated gas gland cells of the European eel Anguilla anguilla

Swimbladder gas gland cells are known to produce lactic acid required for the acidification of swimbladder blood and decreasing the oxygen carrying capacity of swimbladder blood, i.e., the onset of the Root effect. Gas gland cells have also been shown to metabolize glucose via the pentose phosphate shunt, but the role of the pentose phosphate shunt for acid secretion has not yet been evaluated. Similarly, aerobic metabolism of gas gland cells has been largely neglected so far. In the present study, we therefore simultaneously assessed the role of glycolysis and of the pentose phosphate shunt for acid secretion and recorded oxygen consumption of isolated swimbladder gas gland cells of the European eel. Presence of glucose was essential for acid secretion, and at glucose concentrations of about 1.5 mmol l−1 acid secretion of gas gland cells reached a maximum, indicating that glucose concentrations in swimbladder blood should not be limiting acid production and secretion under physiological conditions. The data revealed that most of the acid was produced in the glycolytic pathway, but a significant fraction was also contributed by the pentose phosphate shunt. Addition of glucose to gas gland cells incubated in a glucose-free medium resulted in a reduction of oxygen uptake. Inhibition of mitochondrial respiration significantly reduced oxygen consumption, but a fraction of mitochondria-independent respiration remained in presence of rotenone and antimycin A. In the presence of glucose, application of either iodo-acetate inhibiting glycolysis or 6-AN inhibiting the pentose phosphate shunt did not significantly affect oxygen uptake, indicating an independent regulation of oxidative phosphorylation and of acid production. Inhibition of the muscarinic acetylcholine receptor caused a slight elevation in acid secretion, while forskolin caused a concentration-dependent reduction in acid secretion, indicating muscarinic and c-AMP-dependent control of acid secretion in gas gland cells.

Anti-hypoxia effects of ginseng (Panax Ginseng C A Meyer) oligopeptides in mice

Purpose: To study the anti-hypoxia effects of ginseng oligopeptides (GOPs) in mice.&#x0D; Methods: Mice were randomly assigned to six groups: vehicle control group, whey protein-fed group (0.30 g/kg body weight, BW), and four groups given GOP at doses of 0.075, 0.150, 0.300, 0.600 g/kg BW. All treatments were administered via gavage once a day for a total of 30 days.&#x0D; Results: GOPs significantly extended survival times under normobaric hypoxia, sodium nitrite toxicosis and acute cerebral ischemia. Moreover, GOPs enhanced the levels of RBC, Hb and Hct; decreased brain malonaldehyde (MDA) and lactate contents, enhanced brain lactate dehydrogenase (LDH) activity, and upregulated the mRNA expression levels of hypoxia-inducible factor 1alpha (HIF1α) and vascular endothelial growth factor (VEGF).&#x0D; Conclusion: GOPs exert anti-hypoxia effects via mechanisms which may involve improvement of oxygen-carrying capacity of blood and oxygen utilization, reduction of lipid peroxidation-associated lesions, enhancement of brain capacity to buffer against lactic acidosis, promotion of angiogenesis, and regulation of response to hypoxia.