Hematology, blood volume, and oxygen transport of dogs exposed to high altitude.

Vogel, James A.; Bishop, George W.; Genovese, Ronald L.; Powell, Theresa L.

doi:10.1152/jappl.1968.24.2.203

Cited by 14 publications

(7 citation statements)

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“…Hemoglobin saturation was calculated from blood gas data and temperature (43). Arterial oxygen content was calculated based on the regression equation for hemoglobin concentration during incremental exercise developed by Hsia et al (20), assuming little change with acute hypoxia (49). Group data for each variable are expressed as means Ϯ SE.…”

Section: Discussionmentioning

confidence: 99%

Sympathetic restraint of muscle blood flow during hypoxic exercise

Stickland

Smith²,

Soriano³

et al. 2009

American Journal of Physiology-Regulatory, Integrative and Comp

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Control of exercising muscle blood flow is a balance between local vasodilatory factors and the increase in global sympathetic vasoconstrictor outflow. Hypoxia has been shown to potentiate the muscle sympathetic nerve response to exercise, potentially limiting the increase in muscle blood flow. Accordingly, we investigated sympathetic restraint to exercising muscle during whole body exercise in hypoxia. Six dogs chronically instrumented with ascending aortic and hindlimb flow probes and a terminal aortic catheter were studied at rest and mild [2.5 miles/h (mph), 5% grade] and moderate (4.0 mph, 10% grade) exercise while breathing room air or hypoxia (Pa(O(2)) approximately 45 mmHg) in the intact control condition and following systemic alpha-adrenergic blockade (phentolamine). Hypoxia caused an increase in cardiac output (CO), hindlimb flow (Flow(L)), and blood pressure (BP), while total (Cond(T)) and hindlimb conductance (Cond(L)) were unchanged at rest and mild exercise but increased with moderate exercise. During both mild and moderate exercise, alpha-blockade in normoxia resulted in significant vasodilation as evidenced by increases in CO (10%), Flow(L) (17%), Cond(T) (33%), Cond(L) (43%), and a decrease in BP (-18%), with the increase in Cond(L) greater than the increase in Cond(T) during mild exercise. Compared with the normoxic response, alpha-blockade in hypoxia during exercise resulted in a significantly greater increase in Cond(T) (59%) and Cond(L) (74%) and a correspondingly greater decrease in BP (-34%) from baseline. These findings indicate that there is considerable hypoxia-induced sympathetic restraint of muscle blood flow during both mild and moderate exercise, which helps to maintain arterial blood pressure in hypoxia.

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Section: Discussionmentioning

confidence: 99%

Sympathetic restraint of muscle blood flow during hypoxic exercise

Stickland

Smith²,

Soriano³

et al. 2009

American Journal of Physiology-Regulatory, Integrative and Comp

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“…The duration of documented hypoxemia was considered adequate, because in previous studies the erythropoietic response to hypoxemia was detected within 30 days in dogs and after 2 weeks in humans. 26,49 Overall, in our study we observed that persistent systemic hypoxia caused by chronic lung disease does not commonly result in secondary erythrocytosis in dogs and other mechanisms to accommodate decreased tissue oxygenation are likely. In our study, none of the dogs with chronic hypoxia caused by pulmonary disease had marked erythrocytosis.…”

Section: Discussionmentioning

confidence: 51%

Section: Discussionmentioning

confidence: 99%

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Polycythemia in dogs with chronic hypoxic pulmonary disease

Holopainen

Laurila

Lappalainen

et al. 2022

Veterinary Internal Medicne

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Background: Prolonged tissue hypoxia caused by chronic pulmonary disease is commonly regarded as an important mechanism in the development of secondary polycythemia, but little clinical data are available to support this hypothesis.Objective: To study the prevalence and severity of erythrocytosis accompanying chronic hypoxic pulmonary disease in dogs.Animals: Forty-seven dogs with hypoxic chronic pulmonary disease, 27 dogs with nonhypoxic chronic pulmonary disease, and 60 healthy controls.Methods: Dogs with chronic pulmonary disease and chronic hypoxemia (partial pressure of arterial oxygen [PaO 2 ] < 80 mm Hg on at least 2 arterial blood gas measurements a minimum of 1 month apart) were identified retrospectively from patient records. Association between arterial oxygen and red blood cell parameters was analyzed using Pearson's correlation coefficients and multivariable linear regression analysis.Results: Red blood cell parameters measured at the end of the hypoxemia period were within the laboratory reference range in most dogs. In chronically hypoxemic dogs, hematocrit (Hct) was increased in 4/47 (8.5%; 95% confidence interval [CI], 0-17) dogs, erythrocyte count (Erytr) was increased in 12/47 (26%; 95%CI, dogs and hemoglobin concentration (Hb) was increased in 3/47 (6.4%; 95%CI, 0-14) dogs. No marked polycythemia (Hct ≥65%) was noted in any of the dogs. Red blood cell parameters were not associated with the severity of hypoxemia (correlation to

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“…Los conceptos más relevantes de la fisiología a grandes alturas incluyen presión barométrica, que para Bogotá es 560 mmHg, y presión de O 2 en el ambiente de 117 mmHg (a nivel del mar son 760 mmHg y 159 mmHg, respectivamente) (15). Por otro lado, la presión inspiratoria de oxígeno (PIO 2 ), la presión alveolar de oxígeno (PaO 2 ), así como las diferentes modificaciones orgánicas de los mamíferos para hemoglobina, proteínas plasmáticas, hematocrito, eritropoyetina y circulación pulmonar (8,12,(16)(17)(18)(19)(20)(21) influyen de manera directa e indirecta en el mantenimiento de este valor. Por ejemplo, a nivel alveolar en humanos, en Bogotá los valores de la PO 2 pasan de 100 (a nivel del mar) a 72-77 mmHg, lo cual afectará la diferencia alvéolo-arterial (21).…”

Section: Discussionunclassified

Valores de referencia de gases arteriales y de electrolitos en caninos de la sabana de Bogotá

Jurado¹,

Barros²,

Cortés³

et al. 2014

Rev. Med. Vet.

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Debido a la ausencia de valores de gasometría arterial que se ajusten a nuestras condiciones ambientales y a la amplia variedad de datos no actualizados en la literatura y utilizados en la práctica diaria, obtenidos con alturas, razas y equipos diferentes a los disponibles en nuestro medio, es necesario generar conocimiento propio ajustado a nuestra realidad. Se realizó una medición sistemática al azar de sangre arterial y venosa en 100 caninos sanos a la altura de la sabana de Bogotá (Chía: 2652 msnm; Cajicá: 2558 msnm; Sopó: 2650 msnm; La Calera: 2718 msnm y Bogotá: 2630 msnm), utilizando el analizador I-STAT® con cartucho EG7+. Se encontraron valores de referencia de gasometría, electrolitos, bases efectivas y pH. Los valores fueron comparados entre cuatro grupos por peso. Para cada parámetro se realizó estadística descriptiva basada en promedio, desviación estándar, error estándar, y se hallaron los límites de confianza (95 %) y los intervalos con desviación estándar (una y dos desviaciones). Se evidenció disminución de PCO2, PO2, SO2, bicarbonato, BE. El pH se encontró levemente aumentado, similar a lo reportado por autores a grandes alturas y diferentes (no corroborado estadísticamente) a reportes en literatura, en los que la altura no fue una variable. Aun así son usados frecuentemente como referencia en la práctica de pequeños animales; solo la PO2 presentó diferencias estadísticas por grupos de peso. Como conclusión, se evidenció una regulación del pH sanguíneo eficaz a 2600 msnm, con diferentes valores de bicarbonato, PCO2, PO2, BE, que indican la necesidad de obtener y utilizar valores de referencia acordes con condiciones locales.

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Hematology, blood volume, and oxygen transport of dogs exposed to high altitude.

Cited by 14 publications

References 0 publications

Sympathetic restraint of muscle blood flow during hypoxic exercise

Sympathetic restraint of muscle blood flow during hypoxic exercise

Polycythemia in dogs with chronic hypoxic pulmonary disease

Valores de referencia de gases arteriales y de electrolitos en caninos de la sabana de Bogotá

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