Changes in Myoglobin Content of the High Altitude Acclimatized Rat

1956 ◽  
Vol 185 (3) ◽  
pp. 549-556 ◽  
Author(s):  
Burton E. Vaughan ◽  
Nello Pace
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Hemoglobin Concentration ◽  
The Body ◽  
Whole Body ◽  
Altitude Exposure ◽  
Cell Plasma ◽  
Muscle Groups ◽  
Cellular Oxidation ◽  
Total Body

A method is described for the assay of myoglobin in all myoglobin containing tissues of the rat, in particular the heart and diaphragm. Total body myoglobin increased 70% above sea level values, both in animals taken from sea level to 12,500 feet and in animals born and reared at 12,500 feet. In comparison with the muscle hemoglobin concentration increase of 50%, the blood hemoglobin concentration increased only 25% above sea level values. Whole body content of myoglobin was determined directly, and this amounted to 17.3 mg/100 gm of body weight, or to 42.3 mg/100 gm of wet muscle. Partition of the body myoglobin among seven muscle groups was ascertained. Heart, diaphragm and the two masseters contain only about 10% of the total myoglobin. Evaluation was made of the factors that have been suggested to explain the disparity in the originally reported myoglobin increases at high altitude of Hurtado et al. and more recent work. It is clear that failure to obtain the increase in the rat is attributable to the use of intermittent rather than continuous high altitude exposure. Evidence for full acclimatization in the animals here used was adduced. The suggestion is made that myoglobin maintains an optimal oxygen gradient between the cell plasma membrane and the mitochondria, and in so doing is involved in dynamic relation to cellular oxidation.

The Influence of Altitude on Erythropoietin Resistance Index in Maintenance Hemodialysis Patients: Data from Tibetan Plateau

2020 ◽  
pp. 1-6
Author(s):  
Yan Wang ◽  
Zong-hui Dang ◽  
Liang-ying Gan ◽  
Ciren Luobu ◽  
Lei Zhang ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Resistance Index ◽  
Hemoglobin Concentration ◽  
Maintenance Hemodialysis ◽  
Autonomous Region ◽  
Tibet Autonomous Region ◽  
Dialysis Vintage ◽  
Peking University ◽  
The Impact

Background: It is known that hypoxia influences many of the biologic processes involved in erythropoiesis; therefore, the high-altitude hypoxia may affect erythropoietin (EPO) responsiveness in maintenance hemodialysis (MHD) patients. This study aimed to evaluate the impact of altitude on EPO responsiveness in MHD patients. Methods: In this retrospective study, MHD patients from Tibet Autonomous Region People’s Hospital (3,650 m above sea level) and Peking University People’s Hospital (43.5 m above sea level) were recruited between May 2016 and December 2018. Patients were divided into 2 groups according to altitude. Variables including age, sex, dialysis vintage, dialysis modality, duration of EPO use, EPO doses, and laboratory tests were collected and analyzed. EPO responsiveness was measured in terms of the EPO resistance index (ERI). ERI was defined as the weekly weight-adjusted dose of EPO (IU/kg/week) divided by hemoglobin concentration (g/dL). The association between ERI and altitude was estimated using a multivariable linear regression model. Results: Sixty-two patients from Tibet Autonomous Region People’s Hospital (high-altitude [HA] group) and 102 patients from Peking University People’s Hospital (low-altitude [LA] group) were recruited. The ERI for HA group and LA group was 6.9 ± 5.1 IU w−1 kg−1 (g/dL)−1 and 11.5 ± 6.4 IU w−1 kg−1 (g/dL)−1, respectively. After adjusting for covariates by multivariable regression, altitude was independently associated with ERI (R2 = 0.245, p < 0.001). Conclusion: Altitude had an independent negative correlation with ERI. This result supported the hypothesis that altitude-associated hypoxia improved EPO responsiveness in MHD patients.

Altitude-induced erythrocytic 2,3-DPG and hemoglobin changes in rats of various ages

1975 ◽  
Vol 39 (2) ◽  
pp. 258-261 ◽  
Author(s):  
L. G. Martin ◽  
J. M. Connors ◽  
J. J. McGrath ◽  
J. Freeman
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Age Groups ◽  
Altitude Exposure ◽  
Simulated High Altitude ◽  
Erythropoietic Response ◽  
2,3 Dpg

Rats of various ages (2, 12, 24, and 40 mo of age) were exposed for 4 wk to either a simulated high altitude of 23,000 ft or to a Peoria, Ill., altitude of 650 ft above sea level. Hematocrit ratios, hemoglobin, and erythrocytic 2,3-diphospho-glycerate (2,3-DPG) concentrations were measured. Hematocrit and hemoglobin determinations revealed a decrease in erythrocytic content with increasing age, and the augmented erythropoietic response was seen in all age groups of animals as a result of altitude exposure. The maximal erythrocytic content of hemoglobin in the 40-mo-old animals was significantly lower than that of all other age groups. Erythrocytic 2,3-DPG levels were significantly changed by aging alone. In the 40-mo-old group there was a 35% increase over the next highest sea-level value. However, while erythrocytic 2,3-DPG content increased significantly in all other age groups following altitude exposure, it decreased 46% in the 40-mo-old group.

scholarly journals Effects of baseline heart rate at sea level on cardiac responses to high-altitude exposure

2020 ◽  
Vol 36 (5) ◽  
pp. 799-810
Author(s):  
Jingdu Tian ◽  
Chuan Liu ◽  
Yuanqi Yang ◽  
Shiyong Yu ◽  
Jie Yang ◽  
...  
Keyword(s):  
Heart Rate ◽  
High Altitude ◽  
Sea Level ◽  
Baseline Heart Rate ◽  
Altitude Exposure ◽  
Cardiac Responses

Effects of high altitude and water deprivation on arginine vasopressin release in men

2004 ◽  
Vol 286 (1) ◽  
pp. E20-E24 ◽  
Author(s):  
C. M. Maresh ◽  
W. J. Kraemer ◽  
D. A. Judelson ◽  
J. L. VanHeest ◽  
L. Trad ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Arginine Vasopressin ◽  
Water Deprivation ◽  
Urine Volume ◽  
Plasma Osmolality ◽  
Vasopressin Release ◽  
Altitude Exposure ◽  
Blood Pressures ◽  
Healthy Males

High-altitude exposure changes the distribution of body water and electrolytes. Arginine vasopressin (AVP) may influence these alterations. The purpose of this study was to examine the effect of a 24-h water deprivation trial (WDT) on AVP release after differing altitude exposures. Seven healthy males (age 22 ± 1 yr, height 176 ± 2 cm, mass 75.3 ± 1.8 kg) completed three WDTs: at sea level (SL), after acute altitude exposure (2 days) to 4,300 m (AA), and after prolonged altitude exposure (20 days) to 4,300 m (PA). Body mass, standing and supine blood pressures, plasma osmolality (Posm), and plasma AVP (PAVP) were measured at 0, 12, 16, and 24 h of each WDT. Urine volume was measured at each void throughout testing. Baseline Posm increased from SL to altitude (SL 291.7 ± 0.8 mosmol/kgH2O, AA 299.6 ± 2.2 mosmol/kgH2O, PA 302.3 ± 1.5 mosmol/kgH2O, P < 0.05); however, baseline PAVP measurements were similar. Despite similar Posm values, the maximal PAVP response during the WDT (at 16 h) was greater at altitude than at SL (SL 1.7 ± 0.5 pg/ml, AA 6.4 ± 0.7 pg/ml, PA 8.7 ± 0.9 pg/ml, P < 0.05). In conclusion, hypoxia appeared to alter AVP regulation by raising the osmotic threshold and increasing AVP responsiveness above that threshold.

A Study of Changes in Whole-Body Calcium, Phosphorus, Sodium and Nitrogen by Neutron Activation Analysis in Vivo in Rats on a Calcium-Deficient Diet

1976 ◽  
Vol 51 (4) ◽  
pp. 399-402
Author(s):  
K. Boddy ◽  
R. Lindsay ◽  
I. Holloway ◽  
D. A. S. Smith ◽  
A. Elliott ◽  
...  
Keyword(s):  
Neutron Activation Analysis ◽  
Activation Analysis ◽  
The Body ◽  
Whole Body ◽  
Deficient Diet ◽  
Calcium Phosphorus ◽  
Dietary Period ◽  
Total Body ◽  
And Control

1. A method of measuring changes in the total body content of calcium, phosphorus, nitrogen and sodium in rats by activation analysis in vivo is described. 2. The change in the body content of the elements has been measured in rats on a calcium-deficient diet and in control animals, the body nitrogen being used to represent lean body mass for normalization. 3. There were significant differences in Ca/N and P/N but not in Ca/P ratios between the animals on a deficient diet and control animals at the end of the dietary period.

scholarly journals Cognitive and psychomotor responses to high-altitude exposure in sea level and high-altitude residents of Ecuador

2015 ◽  
Vol 34 (1) ◽  
Author(s):  
John E Davis ◽  
Dale R Wagner ◽  
Nathan Garvin ◽  
David Moilanen ◽  
Jessica Thorington ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Altitude Exposure

scholarly journals Feasibility study of volumetric modulated arc therapy with Halcyon™ linac for total body irradiation

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Takuya Uehara ◽  
Hajime Monzen ◽  
Mikoto Tamura ◽  
Masahiro Inada ◽  
Masakazu Otsuka ◽  
...  
Keyword(s):  
Total Body Irradiation ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Dose Calculation ◽  
Target Volume ◽  
The Body ◽  
Whole Body ◽  
Data Set ◽  
Arc Therapy ◽  
Total Body

Abstract Background The use of total body irradiation (TBI) with linac-based volumetric modulated arc therapy (VMAT) has been steadily increasing. Helical tomotherapy has been applied in TBI and total marrow irradiation to reduce the dose to critical organs, especially the lungs. However, the methodology of TBI with Halcyon™ linac remains unclear. This study aimed to evaluate whether VMAT with Halcyon™ linac can be clinically used for TBI. Methods VMAT planning with Halcyon™ linac was conducted using a whole-body computed tomography data set. The planning target volume (PTV) included the body cropped 3 mm from the source. A dose of 12 Gy in six fractions was prescribed for 50% of the PTV. The organs at risk (OARs) included the lens, lungs, kidneys, and testes. Results The PTV D98%, D95%, D50%, and D2% were 8.9 (74.2%), 10.1 (84.2%), 12.6 (105%), and 14.2 Gy (118%), respectively. The homogeneity index was 0.42. For OARs, the Dmean of the lungs, kidneys, lens, and testes were 9.6, 8.5, 8.9, and 4.4 Gy, respectively. The V12Gy of the lungs and kidneys were 4.5% and 0%, respectively. The Dmax of the testes was 5.8 Gy. Contouring took 1–2 h. Dose calculation and optimization was performed for 3–4 h. Quality assurance (QA) took 2–3 h. The treatment duration was 23 min. Conclusions A planning study of TBI with Halcyon™ to set up VMAT-TBI, dosimetric evaluation, and pretreatment QA, was established.

scholarly journals Abscopal Effect Following Radiation Therapy in Cancer Patients: A New Look from the Immunological Point of View

2019 ◽  
Author(s):  
J Welsh ◽  
J J Bevelacqua ◽  
L Dobrzyński ◽  
S A R Mortazavi ◽  
Sh Farjadian ◽  
...  
Keyword(s):  
Distant Metastasis ◽  
Suppressive Effect ◽  
Point Of View ◽  
The Body ◽  
Whole Body ◽  
High Dose ◽  
Abscopal Effect ◽  
Cancer Treatments ◽  
Key Factor ◽  
Total Body

Abscopal effect, a radiobiology term meaning “away from target”, was practically unheard of just ten years ago. This effect describes the elimination and cure of a non-treated tumor when another part of the body is irradiated. Successful treatment of cancer in patients with multiple metastatic foci has sporadically been reported. Abscopal effect after radiotherapy has been introduced as the key factor which induced an anticancer response in these metastatic lesions. Moreover, not receiving chemotherapy is reported to have a role in cancer regression after radiotherapy. Given this consideration, it can be hypothesized that standard radiotherapy doses, which usually classified as high-dose, may cause cancer cells to expose or release their sequestered antigens that had been previously masked. Furthermore, radiotherapy can decrease the suppressive effect of regulatory T cells which usually down modulate immune responses against cancers. Moreover, some data show that low dose total-body irradiation (TBI) alone (without standard localized high dose radiotherapy) may cause suppression of distant metastasis of tumor cells. Induction of a “whole body abscopal effect” can be involved in suppression of distant metastasis. Here we discuss whether cancer treatments could be more successful if immune system is boosted, not destroyed by the treatments such as chemotherapy.

scholarly journals Mice and Rats Display Different Ventilatory, Hematological, and Metabolic Features of Acclimatization to Hypoxia

2021 ◽  
Vol 12 ◽  
Author(s):  
Christian Arias-Reyes ◽  
Jorge Soliz ◽  
Vincent Joseph
Keyword(s):  
High Altitude ◽  
Minute Ventilation ◽  
Rattus Rattus ◽  
Hemoglobin Concentration ◽  
Whole Body ◽  
Ecological Niches ◽  
House Mice ◽  
Sprague Dawley ◽  
Mitochondrial Oxygen Consumption ◽  
Sd Rats

Phylogeographic studies showed that house mice (Mus musculus) originated in the Himalayan region, while common rats (Rattus rattus and Rattus norvegicus) come from the lowlands of China and India. Accordingly, it has been proposed that its origins gave mice, but not rats, the ability to invade ecological niches at high altitudes (pre-adaptation). This proposal is strongly supported by the fact that house mice are distributed throughout the world, while common rats are practically absent above 2,500 m. Considering that the ability of mammals to colonize high-altitude environments (&gt;2,500 m) is limited by their capability to tolerate reduced oxygen availability, in this work, we hypothesize that divergences in the ventilatory, hematological, and metabolic phenotypes of mice and rats establish during the process of acclimatization to hypoxia (Hx). To test this hypothesis male FVB mice and Sprague-Dawley (SD) rats were exposed to Hx (12% O2) for 0 h (normoxic controls), 6 h, 1, 7, and 21 days. We assessed changes in ventilatory [minute ventilation (VE), respiratory frequency (fR), and tidal volume (VT)], hematological (hematocrit and hemoglobin concentration), and metabolic [whole-body O2 consumption (VO2) and CO2 production (VCO2), and liver mitochondrial oxygen consumption rate (OCR) parameters]. Compared to rats, results in mice show increased ventilatory, metabolic, and mitochondrial response. In contrast, rats showed quicker and higher hematological response than mice and only minor ventilatory and metabolic adjustments. Our findings may explain, at least in part, why mice, but not rats, were able to colonize high-altitude habitats.

Interleukin-6 response to exercise and high-altitude exposure: influence of α-adrenergic blockade

2001 ◽  
Vol 91 (5) ◽  
pp. 2143-2149 ◽  
Author(s):  
Robert S. Mazzeo ◽  
Danielle Donovan ◽  
Monika Fleshner ◽  
Gail E. Butterfield ◽  
Stacy Zamudio ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Interleukin 6 ◽  
Moderate Intensity ◽  
Adrenergic Blockade ◽  
Moderate Intensity Exercise ◽  
Exercise Tests ◽  
Altitude Exposure ◽  
Excretion Rates ◽  
Response To Exercise

Interleukin-6 (IL-6), an important cytokine involved in a number of biological processes, is consistently elevated during periods of stress. The mechanisms responsible for the induction of IL-6 under these conditions remain uncertain. This study examined the effect of α-adrenergic blockade on the IL-6 response to acute and chronic high-altitude exposure in women both at rest and during exercise. Sixteen healthy, eumenorrheic women (aged 23.2 ± 1.4 yr) participated in the study. Subjects received either α-adrenergic blockade (prazosin, 3 mg/day) or a placebo in a double-blinded, randomized fashion. Subjects participated in submaximal exercise tests at sea level and on days 1 and 12 at altitude (4,300 m). Resting plasma and 24-h urine samples were collected throughout the duration of the study. At sea level, no differences were found at rest for plasma IL-6 between groups (1.5 ± 0.2 and 1.2 ± 0.3 pg/ml for placebo and blocked groups, respectively). On acute ascent to altitude, IL-6 levels increased significantly in both groups compared with sea-level values (57 and 84% for placebo and blocked groups, respectively). After 12 days of acclimatization, IL-6 levels remained elevated for placebo subjects; however, they returned to sea-level values in the blocked group. α-Adrenergic blockade significantly lowered the IL-6 response to exercise both at sea level (46%) and at altitude (42%) compared with placebo. A significant correlation ( P = 0.004) between resting IL-6 and urinary norepinephrine excretion rates was found over the course of time while at altitude. In conclusion, the results indicate a role for α-adrenergic regulation of the IL-6 response to the stress of both short-term moderate-intensity exercise and hypoxia.

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