Blood Hb Concentration Research Articles

Effect of chronic sodium cyanate administration on O2 transport and uptake in hypoxic and normoxic exercise.

Systemic O2 transport during maximal exercise at different inspired PO2 (PIO2) values was studied in sodium cyanate-treated (CY) and nontreated (NT) rats. CY rats exhibited increased O2 affinity of Hb (exercise O2 half-saturation pressure of Hb = 27.5 vs. 42.5 Torr), elevated blood Hb concentration, pulmonary hypertension, blunted hypoxic pulmonary vasoconstriction, and normal ventilatory response to exercise. Maximal rate of convective O2 transport was higher and tissue O2 extraction was lower in CY than in NT rats. The relative magnitude of these opposing changes, which determined the net effect of cyanate on maximal O2 uptake (VO2 max), varied at different PIO2: VO2 max (ml. min-1. kg-1) was lower in normoxia (72.8 +/- 1.9 vs. 81. 1 +/- 1.2), the same at 70 Torr PIO2 (55.4 +/- 1.4 vs. 54.1 +/- 1.4), and higher at 55 Torr PIO2 (48 +/- 0.7 vs. 40.4 +/- 1.9) in CY than in NT rats. The beneficial effect of cyanate on VO2 max at 55 Torr PIO2 disappeared when Hb concentration was lowered to normal. It is concluded that the effect of cyanate on VO2 max depends on the relative changes in blood O2 convection and tissue O2 extraction, which vary at different PIO2. Although uptake of O2 by the blood in the lungs is enhanced by cyanate, its release at the tissues is limited, probably because of a reduction in the capillary-to-tissue PO2 diffusion gradient secondary to the increased O2 affinity of Hb.

Human Cardiovascular and Metabolic Response to Acute, Severe Isovolemic Anemia

Context.—Although concern over the risks of red blood cell transfusion has resulted in several practice guidelines for transfusion, lack of data regarding the physiological effects of anemia in humans has caused uncertainty regarding the blood hemoglobin (Hb) concentration requiring treatment.Objective.—To test the hypothesis that acute isovolemic reduction of blood Hb concentration to 50 g/L in healthy resting humans would produce inadequate cardiovascular compensation and result in tissue hypoxia secondary to inadequate oxygen transport.Design.—Before and after interventional study.Setting.—Academic tertiary care medical center.Participants.—Conscious healthy patients (n=11) prior to anesthesia and surgery and volunteers not undergoing surgery (n=21).Interventions.—Aliquots of blood (450-900 mL) were removed to reduce blood Hb concentration from 131 (2) g/L to 50 (1) g/L [mean (SE)]. Isovolemia was maintained with 5% human albumin and/or autologous plasma. Cardiovascular parameters, arterial and mixed venous oxygen content, oxyhemoglobin saturation, and arterial blood lactate were measured before and after removal of each aliquot of blood. Electrocardiogram and, in a subset, Holter monitor were monitored continuously.Main Outcome Measures.—Critical oxygen delivery (TO2) as assessed by oxygen consumption (O2), plasma lactate concentration, and ST changes on electrocardiogram.Results.—Acute, isovolemic reduction of Hb concentration decreased systemic vascular resistance and TO2 and increased heart rate, stroke volume, and cardiac index (each P<.001). We did not find evidence of inadequate oxygenation: O2 increased slightly from a mean (SD) of 3.07 (0.44) mL of oxygen per kilogram per minute (mL O2·kg−1·min−1) to 3.42 (0.54) Ml O2·kg−1·min−1 (P<.001) and plasma lactate concentration did not change (0.81 [0.11] mmol/L to 0.62 [0.19] mmol/L;P=.09). Two subjects developed significant ST changes on Holter monitor: one apparently related to body position or activity, the other to an increase in heart rate (at an Hb concentration of 46-53 g/L); both occurred in young women and resolved without sequelae.Conclusions.—Acute isovolemic reduction of blood Hb concentration to 50 g/L in conscious healthy resting humans does not produce evidence of inadequate systemic TO2, as assessed by lack of change of O2 and plasma lactate concentration. Analysis of Holter readings suggests that at this Hb concentration in this resting healthy population, myocardial ischemia would occur infrequently.

Does the Hemoglobin Concentration in Fetal Blood Interfere with the Accuracy of Fetal Reflection Pulse Oximetry?

Objective: Our goal was to investigate the influence of the fetal hemoglobin (Hb) concentration on the accuracy of reflection pulse oximetry. Methods: 179 fetuses were monitored by a reflection pulse oximetry system (RPOX MK2). Pulse oximetry measurements (SO_2POX) were compared with the oxygen saturation and pH of umbilical artery and vein (UA-, UV-SaO₂) immediately after delivery. Correlation and linear regression analyses were performed. Because it is unknown whether low or high Hb concentrations might interfere with the SO_2POX measurements, the influence of the Hb level on the correlations was evaluated by weighting the linear regression in both ways; by Hb concentrations as weighting factor and as an inverse weighting factor (1/Hb). Results: There was a significant correlation between SO_2POX and UV-SaO₂ (for the last 10 min of delivery, r = 0.45, p < 0.0005) but not with pH or UA-SaO₂. Linear regression analysis between SO_2POX and UV-SaO₂ showed a multiple R of 0.45. Hb concentration in fetal blood ranged from 9.2 to 20.5 mg/dl. The weighted regression indicated a multiple R_Hb of 0.49, which did not differ by the inverse weighting (multiple R_{inverse Hb}: 0.49). Conclusions: Pulse oximetry measurements seem to reflect oxygen saturation in fetal blood, however further improvement is necessary. The Hb concentration in fetal blood does not interfere with the accuracy of fetal pulse oximetry and need not be taken into consideration in calibration curves.

Rectal mucosal hemodynamics, evaluated by reflectance spectrophotometry, in patients with chronic hepatitis.

To evaluate rectal mucosal hemodynamics in patients with chronic hepatitis, we employed reflectance spectrophotometry and examined the results in relation to the presence and severity of chronic hepatitis. Twenty-six patients with histologically diagnosed chronic hepatitis and 21 controls were examined for rectal vascular findings by endoscopy. Indices (I) of rectal mucosal oxygen saturation (ISO2) and rectal mucosal hemoglobin (IHb) concentration were measured. To minimize the effects of systemic anemia, the IHb was divided by blood Hb concentration, giving the rectal index for Hb (RHb). The relationship between rectal mucosal hemodynamics and the histological grade of chronic hepatitis was studied. Rectal vascular lesions were observed in three patients with chronic hepatitis (11.5%). The RHb in patients with chronic hepatitis was significantly higher than that in the controls (5.74 +/- 0.71 and 4.82 +/- 1.12, respectively; P < 0.01). There was no significant difference in ISO2 levels (44.23 +/- 5.84 and 41.94 +/- 4.91, respectively). No significant correlation was observed between rectal mucosal hemodynamics and the histological severity of chronic hepatitis, although rectal mucosal hemodynamics changed in patients with chronic hepatitis. Early vascular changes were observed in the rectal mucosa of patients with chronic hepatitis.

Acute and subchronic immunotoxicity of p-chloronitrobenzene in mice. I. Effect on natural killer, cytotoxic T-lymphocyte activities and mitogen-stimulated lymphocyte proliferation

We evaluated the immunotoxicity of p-chloronitrobenzene ( p-CNB) after intraperitoneal (ip) injection of p-CNB in BDF1 mice; single ip injection of 300 mg/kg (acute experiments), or 30 mg/kg three times a week for 4 weeks (subchronic experiments). The following items were investigated: number of splenocytes, natural killer (NK) activity, cytotoxic T-lymphocyte (CTL) activity and LPS-stimulated lymphocyte proliferation using splenocytes, hemoglobin (Hb) concentration in peripheral blood and body weight. NK activity in exposed mice significantly decreased compared to control in both acute and subchronic experiments. CTL activity in acute exposed mice showed a significant decrease on the 3rd day only after injection, and significant decrease at 3 and 4 weeks in subchronic exposed mice compared to controls. Comparing the effect of p-CNB on NK activity with that of CTL for both the acute and subchronic exposures, NK activity was more inhibited by p-CNB than CTL activity in the acute stage, whereas both the NK and CTL activities were inhibited by p-CNB in the subchronic stage. There was an indication that p-CNB also inhibited LPS- stimulated B-lymphocyte proliferation. On the other hand, Hb concentration did not show significant difference between the exposed and control mice in both acute and subchronic experiments. Body weight in subchronically exposed mice was significantly lower than the control from day 19. The above evidence indicated that p-CNB has an inherent immunotoxic effect on mice.

Human cardiovascular and metabolic response to acute, severe isovolemic anemia.

Although concern over the risks of red blood cell transfusion has resulted in several practice guidelines for transfusion, lack of data regarding the physiological effects of anemia in humans has caused uncertainty regarding the blood hemoglobin (Hb) concentration requiring treatment. To test the hypothesis that acute isovolemic reduction of blood Hb concentration to 50 g/L in healthy resting humans would produce inadequate cardiovascular compensation and result in tissue hypoxia secondary to inadequate oxygen transport. Before and after interventional study. Academic tertiary care medical center. Conscious healthy patients (n =11) prior to anesthesia and surgery and volunteers not undergoing surgery (n=21). Aliquots of blood (450-900 mL) were removed to reduce blood Hb concentration from 131 (2) g/L to 50 (1) g/L [mean (SE)]. Isovolemia was maintained with 5% human albumin and/or autologous plasma. Cardiovascular parameters, arterial and mixed venous oxygen content, oxyhemoglobin saturation, and arterial blood lactate were measured before and after removal of each aliquot of blood. Electrocardiogram and, in a subset, Holter monitor were monitored continuously. "Critical" oxygen delivery (TO2) as assessed by oxygen consumption (VO2), plasma lactate concentration, and ST changes on electrocardiogram. Acute, isovolemic reduction of Hb concentration decreased systemic vascular resistance and TO2 and increased heart rate, stroke volume, and cardiac index (each P<.001). We did not find evidence of inadequate oxygenation: VO2 increased slightly from a mean (SD) of 3.07 (0.44) mL of oxygen per kilogram per minute (mL O2 x kg(-1) x min[-1]) to 3.42 (0.54) mL O2 x kg(-1) x min(-1) (P<.001) and plasma lactate concentration did not change (0.81 [0.11] mmol/L to 0.62 [0.19] mmol/L; P=.09). Two subjects developed significant ST changes on Holter monitor: one apparently related to body position or activity, the other to an increase in heart rate (at an Hb concentration of 46-53 g/L); both occurred in young women and resolved without sequelae. Acute isovolemic reduction of blood Hb concentration to 50 g/L in conscious healthy resting humans does not produce evidence of inadequate systemic TO2, as assessed by lack of change of VO2 and plasma lactate concentration. Analysis of Holter readings suggests that at this Hb concentration in this resting healthy population, myocardial ischemia would occur infrequently.

Effect of hemoglobin status on humoral immune response of weanling pigs differing in coping styles.

The effects of hemoglobin (Hb) status and coping style of pigs on performance and humoral immune response were studied. Twenty-four, 4-wk-old crossbred barrows were assigned to groups of three pigs based on weight and litter origin. Groups were allotted according to a 2 x 2 factorial treatment arrangement: two blood Hb concentration classes (low vs high) and two immunization procedures (control vs immunized). Immunized pigs received an antigen cocktail containing keyhole limpet hemocyanin (KLH), ovalbumin (OA), and tetanus toxoid (TT) at weaning. Additionally, pigs were stratified according to behavioral coping style in response to exposure to a stressor. During 41 d after weaning (approximate time of immunization), blood Hb concentration, ADG, and ADFI were measured weekly and serum antibody titers to KLH, OA, and TT twice weekly. Average Hb concentration differed between low and high Hb pigs (P < .001; 10.0 vs 12.0 g/dL), but this difference declined with time after weaning. Neither immunization procedure nor coping style affected Hb concentrations. In addition, ADG and ADFI were unaffected by any of the treatments. However, ADG was slightly greater in high Hb status pigs (586 vs 633 g/d) and was paralleled by a slightly greater ADFI in high Hb status pigs (812 vs 899 g/d). Antibody responses were negatively or not related to Hb status at weaning. Antibody responses (depending on isotype and antigen) were or tended to be lower in pigs with high blood Hb concentrations. Behavioral coping style strongly affected humoral immune responsiveness; enhanced or accelerated antibody responses were found in pigs that had a passive coping style.

Evaluation of an automated system for hemoglobin measurement in animals

SUMMARY In veterinary medicine, pcv determined by centrifugation of blood in a microhematocrit tube is the most common clinical test used to initially assess and monitor anemic and polycythemic animals. In contrast, blood hemoglobin (Hb) concentration, rather than pcv, is generally determined in human patients. One automated system photometrically measures blood Hb concentration after conversion of Hb to azide methemoglobin without dilution and was found to be a simple and accurate instrument for use in human medicine. We evaluated the system for its accuracy in measuring blood Hb concentration in animals by comparing it with standard techniques and for its suitability in veterinary practice. Blood samples, anticoagulated with potassium edta, from 78 healthy animals (33 dogs, 17 cats, 13 horses, and 15 cows) and 58 dogs and 4 cats with various blood abnormalities (10 anemia, 11 polycythemia, 21 lipemia, 16 leukocytosis, and 6 icterus) were analyzed. In all species, blood Hb concentration of healthy animals determined by the system was comparable to that measured by standard cyanmethemoglobin methods (ie, an automated counter; rI = 0.987 to 0.998 and a hemoglobin kit, rI = 0.946 to 0.993). The aforementioned system also yielded similar values to those obtained by use of standard methods in anemic, polycythemic and icteric dogs and cats. Moreover, the system reads the absorbance at 2 wavelengths to correct for turbidity, and therefore, accurately measured Hb concentration in blood samples with severe lipemia (triglycerides concentration &gt; 500 mg/dl) and marked leukocytosis (&gt; 50,000 wbc/μl, whereas other standard Hb techniques are known to give falsely high results. We conclude that the automated system compares favorably to standard methods, and is a simple and accurate instrument to quickly measure Hb concentration in animals.

A preliminary study of the bio availability of iron‐ and zinc‐glycine chelates

Groups of rats were fed diets containing marginal levels of Fe and Zn as glycine chelates (tradename 'Chelazome', Albion Laboratories, Verona, New Jersey, USA), or the same level of mineral as ferrous sulphate or zinc carbonate. The Fe diets were fed to weanling rats for 4 weeks and the Zn diets to young adult rats for 5 weeks. Blood Hb concentrations were significantly higher in the group fed Fe-chelazome than ferrous sulphate, 149 and 128 g/l respectively (P less than 0.001), but PCV and liver Fe concentrations were similar between the two groups. No difference in plasma Zn, pancreas, testes or femur Zn concentrations were observed between the two Zn groups, indicating that Zn-chelazome has no advantage over zinc carbonate. The results of this preliminary study indicate that Fe-chelazome has a higher bioavailability than ferrous sulphate and merits further study.

The indirect estimation of hemoglobin concentration in whole blood

The present conventional methods for determination of Hemoglobin (Hb) concentration in whole blood depend on the direct colorimetric measurement of chemically modified Hb following its release from red cells by lysis. This paper examines an alternative, indirect method which does not require initial red cell lysis, corrects for the falsely elevated Hb due to the lipemic plasma and determines whether elevated WBC count effects a change in the Hb value, without the tedious laboratory manipulations currently required to correct for these artifacts. The method is simple, uncomplicated and is based on the observation of a constant ratio (2.98) between the Mean Corpuscular Volume (MCV) and the Mean Corpuscular Hemoglobin (MCH) indices obtained from standard electronic counters in use in most laboratories. The Hb concentration is calculated by the equation: [formula: see text]. The resultant Hb measurements show an acceptable degree of accuracy and precision when compared with the direct measurements obtained from a Coulter Model S + I, even in the presence of a high WBC or lipid.

Effect of recombinant human erythropoietin on anticancer drug‐induced anaemia

Anaemia was induced in rats with fluorouracil (5-FU) or cisplatin (CDDP) and the mechanisms of anaemia induction were analysed. Furthermore, the therapeutic effects of recombinant human erythropoietin (rHu Epo) on these anticancer drug-induced anaemias were investigated. In 5-FU-induced anaemia, marked serum erythropoietin (Epo) elevation was observed in inverse correlation to blood Hb concentration and Hb concentration rapidly recovered to normal levels. On the other hand, in CDDP-induced anaemia, serum Epo elevation was modest and the lowered Hb concentration persisted longer. Treatment with rHu Epo significantly improved both anticancer drug-induced anaemias but rHu Epo was more effective on CDDP-induced anaemia. These results suggest that rHu Epo might be useful for the therapy of anaemia associated with anticancer chemotherapy.

THREE-MONTH SUBACUTE ORAL TOXICITY STUDY OF MOFEZOLAC (N-22) IN DOGS

Mofezolac (N-22) is a new developed analgesic and anti-inflammatory agent. A subacute oral toxicity test of N-22 was carried out at dose-levels of 0, 2, 6 and 20 mg/kg/day using male and female beagle dogs. Treatment for 3 months was followed by 1 month recovery period except in the case of both sexes receiving 20 mg/kg/day. The results obtained from the present study were as follows. 1. Observation of general conditions revealed vomiting, sporadic bloody feces, anemia, recumbency and hyposthenia in both sexes receiving 20 mg/kg/day. Anemia or erosion of tongue was observed in each female receiving 6 mg/kg/day. 2. Respectively 3 dogs of both sexes receiving 20 mg/kg/day died during dosing period. In these animals, perforating ulcers were observed in the pars pylorica ventriculi or duodenum, and loss of blood, peritonitis and aggravation of general exhaustion were considered as causes of death. 3. Body weight tended to decrease in both sexes receiving 20 mg/kg/day, and food and water consumption levels decreased in males receiving 2 mg/kg/day or above and females receiving 2 mg/kg/day. 4. Urinalysis demonstrated an increasing tendency for specific gravity of urine and a decreasing tendency for urine volume in males receiving 2 mg/kg/day or above. 5. Hematological examination showed decreases in red blood cell count and Hb concentration in males receiving 2 mg/kg/day or above, and in Ht values in males receiving 6 mg/kg/day or above. 6. Serum biochemical examination revealed decreases in total protein and albumin in both sexes receiving 20 mg/kg/day. 7. There were no remarkable changes in hepatic and renal function, ophthalmological findings or electrocardiogram. 8. In the organ weights, significant decrease in thymus weights was observed in the dead animals receiving 20 mg/kg/day. 9. Pathologically, the dead animals receiving 20 mg/kg/day were found to exhibit peritonitis with perforating ulcers in the pars pylorica ventriculi or duodenum. In the surviving animals of this group, scar ulcers in the pars pylorica ventriculi and small intestine were evident on necropsy, and histopathology revealed neutrophils infiltration and thrombosis in blood vessels in the thickened submucosal stomach tissues. Moreover, localized hepatocyte necrosis and intrasinusoidal cellular infiltration in liver, as well as interstitial cellular infiltration, degeneration and dilatation of the renal tubules in the kidney were observed. In females receiving 6 mg/kg/day, the changes in kidney were similar to those in surviving animals receiving 20 mg/kg/day, and male of the group showed atrophy of thymus.(ABSTRACT TRUNCATED AT 400 WORDS)

Beta-adrenergic influence on increased myocardial oxygen consumption during hypoxemia in awake newborn lambs.

The purpose of this investigation was to determine the role of increased beta-adrenergic activity in regulating the increase in myocardial oxygen consumption that occurs during hypoxemia in unanesthetized newborn lambs. Through a left thoracotomy, fluid-filled catheters were placed in the ascending aorta, coronary sinus and left atrium, a pressure transducer was introduced into the left ventricle, and pacing wires were sutured onto the left atrium. The lambs were studied 3 d later by making intermittent measurements of aortic and coronary sinus blood oxygen saturations and Hb concentrations, left ventricular myocardial blood flow, cardiac output, heart rate, left atrial and aortic blood pressures, the maximal first derivative of left ventricular pressure, aortic and coronary sinus blood oxygen contents, the arteriovenous difference of oxygen across the left ventricular myocardium, myocardial oxygen consumption, and external cardiac work (aortic mean blood pressure times cardiac output). In nine lambs with an intact beta-adrenergic nervous system (group 1), the above measurements were made during a control period and during hypoxemia (FiO2 = 0.08-0.10) with spontaneous tachycardia. In another group of 12 lambs (group 2), the measurements were made during a control period, after beta-blockade (1.5 mg/kg intravenous propranolol) with pacing at the control heart rate, during hypoxemia with pacing at the control heart rate, and during hypoxemia with pacing-induced tachycardia. In the group 2 lambs, beta-blockade completely inhibited the increase in heart rate, maximal first derivative of left ventricular pressure, cardiac output and cardiac work that occurred during hypoxemia in the group 1 lambs that had an intact beta-adrenergic nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of acute umbilical cord compression on hepatic carbohydrate metabolism in the fetal lamb.

Although the liver plays a central role in glucose homeostasis in the adult, its importance in fetal glucose homeostasis during acute reductions of substrate delivery is unknown. To examine this, we studied eight fetal lambs at 121 +/- 2 d gestation. We placed catheters in the descending aorta, inferior vena cava umbilical vein and the left (n = 6) or right (n = 2) hepatic vein, and a balloon occluder around the umbilical cord. At least 4 d after surgery, before and during umbilical cord compression, we measured blood oxygen saturation, glucose, lactate, and Hb concentrations, and blood flows using the radiolabeled microsphere technique. Gluconeogenesis was assessed by infusion of [U14C]lactate. Reducing umbilical flow by 50-60% from a control value of 181 +/- 20 mL/min/kg (mean +/- SD) caused a dramatic decrease in hepatic blood flow from 332 +/- 99 to 94 +/- 77 mL/min/100 g (p less than 0.05). Oxygen delivery to the fetus fell by 50% and that to the liver by 73%. However, hepatic O2 consumption was maintained by increased extraction. Glucose delivery to the liver fell from 67 +/- 24 to 20 +/- 13 mg/min/100 g (p less than 0.001), but lactate delivery did not change. In spite of the maintenance of lactate delivery, net hepatic lactate uptake fell significantly from 3.3 +/- 1.7 to 1.4 +/- 0.9 mg/min/100 g (p less than 0.05). This could account, in part, for the increase of blood lactate concentration from 16 +/- 4 to 27 +/- 7 mg/dl.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of alcoholic beverages on iron and zinc metabolism in the rat.

1. Male Wistar rats (approximately 200 g) were given distilled water and a semi-synthetic control diet for 6 d. On day 7, 37 kBq 65Zn were administered intramuscularly and the rats were given distilled water, beer, cider, red wine, whisky or ethanol as their only source of fluid. The wine, whisky and ethanol were diluted so that each of the beverages contained a similar ethanol concentration (approximately 30 g/l). Food and fluid intake, growth rate and whole-body 65Zn were measured regularly over 11 d, after which animals were killed and blood haemoglobin (Hb) concentration, liver iron stores and the Zn concentration in testes determined. 2. There were no differences in body-weight gain or food intake between groups but fluid intake for the beer group was considerably higher than that for the other groups. 3. There was a significant effect of the type of alcoholic beverage consumed on whole-body 65Zn retention. Rats given whisky had a smaller daily loss of 65Zn than those given water, beer or cider. The ethanol group also showed a lower rate of 65Zn loss compared with the water group. The observed changes in whole-body 65Zn retention could be explained by an adverse influence of ethanol on Zn absorption from the diet. 4. Blood Hb and testes Zn concentration were similar in all groups but the type of liquid consumed influenced liver Fe levels. The cider group had the lowest liver Fe values and the ethanol group the highest values. 5. It is apparent from the present study that ethanol and alcoholic beverages affect Zn and Fe metabolism, but that the effects of ethanol are moderated by other components of the alcoholic beverages.

ラットの血液性状, 筋重量, および運動能に及ぽす飼料鉄水準と水泳トレーニングの影響

This study was carried out to clarify the physiological effects of swimming training and dietary iron intake on rats. Fifty-seven male 15 weeks old rats were divided into three groups of different diets: low (L),medium (M) or high (H) iron diet. They were fed with the diets and water ad libtum during the experiment. After 4.5 weeks, rats in each diet group were divided into two sub-groups: control (Cr) and trained (Tr) rats. Cr rats were subjected to swimming for 10 minutes 3 days per week for 5 weeks in order to be familiarized with swimming, while Tr rats were trained with swimming for 60 minutes 5 days per Week for 5 weeks. After 5 weeks, Cr and Tr rats were forced to swim until exhaustion for determining their endurance performance. The training tended to increase blood hemoglobin (Hb) concentration and relative muscle weight (muscle weight/body weight) of soleus in H and M groups except in L. The relative muscle weights of soleus of Cr and Tr groups and Hb concentration of Tr groups tended to be increased with higher iron content in the diet. There was, however, no significant difference in the endurance swimming performance of Cr or Tr group among three dietary groups. These results indiucated that the dietary iron intake with swimming training increased the relative muscle weight of soleus and Hb concentration in blood, but could not improve the swimming performance.

Allometry of red cell oxygen binding and hematology in larvae of the salamander, Ambystoma tigrinum

Very few studies have attempted to relate blood characteristics to body mass within, rather than between, species. Thus, respiratory and hematological properties of the blood of larval tiger salamanders ( Ambystoma tigrinum) have been measured in animals ranging in body mass from approximately 2 to 112 g. This amphibian species was chosen because larvae of very different body mass may be of similar developmental stage, minimizing interference from ontogenetic factors. Mean corpuscular volume, mean corpuscular Hb, hematocrit, blood Hb concentration, blood O 2 capacity and Hill's n were all positively correlated with body mass ( P < 0.005). Blood O 2 affinity (P 50) and Bohr shift were not significantly correlated with body mass ( P > 0.20). The findings are discussed in the context of the general effect of body mass upon metabolic rate in vertebrates, as well as environmental and biological factors specific to larvae of the tiger salamander.

Effects of Dietary Iron Deficiency on Muscle Fiber Characteristics and Whole-Body Distribution of Hemoglobin in Mice

Effects of dietary iron deficiency on growth, the distribution of hemoglobin (Hb) at rest and during exercise, the characteristics of muscle fiber types, and glycogen depletion patterns were studied in newly weaned male mice. Forty-eight mice were randomly divided into iron-deficient and control diet groups. Severe iron deficiency impaired general growth, but growth was restored following iron repletion. The mean ± SEM blood Hb concentrations at rest after 7 weeks were 5.8 ± 0.7 and 12.5 ± 0.3 g/dl in iron-deficient and control groups, respectively. The mice fed irondeficient diet for 7 weeks had an increased Hb level of 10.9 ± 0.5 g/dl 1 week after an i.p. injection of Imferon (1.25 mg Fe). The Hb contents in brain and gastrocnemius as well as whole body were lowered by iron deficiency. Iron-deficient anemic mice tended to increase the percent distribution of Hb to brain during exercise. This value was significantly greater than in control and iron-treated groups. The iron-deficient group had relatively less glycogen than controls, but no significant tendency in glycogen depletion pattern was observed in any fiber types. It is suggested that decreased Hb content in working muscles due, in part, to greater distribution to brain could be one of the limiting factors for work performance in anemic individuals. It is further suggested that decrease in oxidative muscle fibers as well as the decreased concentration and/or activities of oxidative substances may also be one of the limiting factors.

Marginal malnutrition in school-aged Colombian boys: functional consequences in maximum exercise

The maximum treadmill oxygen consumption was measured in 1013 boys, 6 to 16 yr of age classified as nutritionally normal, low weight for age and low weight for height in upper socioeconomic urban and lower socioeconomic urban and rural groups. The marginally malnourished children (low weight for age and height) in both lower socioeconomic urban and rural groups had significantly depressed maximum treadmill oxygen consumption (85%) compared to normal boys, associated with smaller body weights. It is suggested that the reduced body size and maximum treadmill oxygen consumption resulting from marginal malnutrition during growth will have a detrimental effect on work capacity and productivity of these children when they become engaged in heavy physical work as adults. There was no statistically significant correlation between blood Hb concentration (approximately 10 to 15 g x dl-1) and aerobic capacity.

The blood haemoglobin concentration of the atlantic mackerel ( Scomber scombrus L.)

1. 1. A mean blood haemoglobin (Hb) concentration of 10.3 ± 0.37(30) g/100 ml [x̄ ± SE (n)] was found for mackerel subjected to the minimum of stress before sampling. 2. 2. Mackerel showing a body colour change known to be associated with the fish having been stressed showed a mean blood Hb concentration of 13.4 ± 0.35(5) g/100 ml which is significantly different ( P < 0.001) from the unstressed fish value. 3. 3. Stress induced haemoconcentration may account for the high mean Hb values quoted for mackerel in the literature. 4. 4. The relationship between the packed cell volume (PCV) value for mackerel blood and the Hb concentration was found to be Hb (g/100 ml) = 0.278 PCV (%) + 0.83 ( r = +0.92).