scholarly journals Features of Development of Organism Adaptation under the Conditions of Experimental Acute Hypoxia Depending on Baseline of Autonomic Support

2016 ◽  
Vol 2016 (3) ◽  
pp. 16-24
Author(s):  
L PANINA ◽  
Keyword(s):  
Acute Hypoxia ◽  
Autonomic Support

Desintegration of brain regulatory mechanisms under acute hypoxia

2007 ◽  
Author(s):  
S. I. Soroko ◽  
S. S. Bekshaev ◽  
V. P. Rozhkov
Keyword(s):  
Acute Hypoxia ◽  
Regulatory Mechanisms

Continuous Adaptation of Rats to Hypobaric Hypoxia Prevents Stressor Hyperglycemia and Optimizes Mitochondrial Respiration in Acute Hypoxia

2013 ◽  
Vol 4 (2) ◽  
pp. 137-147
Author(s):  
Vladimir I. Portnichenko ◽  
Valentina I. Nosar ◽  
Alla M. Sydorenko ◽  
Alla G. Portnychenko ◽  
Irina N. Mankovska
Keyword(s):  
Mitochondrial Respiration ◽  
Hypobaric Hypoxia ◽  
Acute Hypoxia

Roles of the Hypoximir microRNA-424/322 on Acute Hypoxia and Hypoxia-Induced Pulmonary Vascular Leakage

2018 ◽  
Author(s):  
Shih-Hung Tsai ◽  
Po-Hsun Huang ◽  
Yu-Juei Hsu ◽  
Yen-Wen Chen ◽  
Jen-Chun Wang ◽  
...  
Keyword(s):  
Acute Hypoxia ◽  
Vascular Leakage

The Time-Course of Changes in the State of Brain Monoaminergic Systems of Mice Under the Acute Hypoxia with Hypercapnia

2020 ◽  
Vol 14 (2) ◽  
pp. 136-149
Author(s):  
I. V. Karpova ◽  
V. V. Mikheev ◽  
V. V. Marysheva ◽  
N. A. Kuritcyna ◽  
E. R. Bychkov ◽  
...  
Keyword(s):  
Time Course ◽  
Acute Hypoxia ◽  
The State ◽  
Hypoxia With Hypercapnia

scholarly journals Spleen contraction elevates hemoglobin concentration at high altitude during rest and exercise

2020 ◽  
Vol 120 (12) ◽  
pp. 2693-2704
Author(s):  
Erika Schagatay ◽  
Alexander Lunde ◽  
Simon Nilsson ◽  
Oscar Palm ◽  
Angelica Lodin-Sundström
Keyword(s):  
High Altitude ◽  
Acute Hypoxia ◽  
Arterial Oxygen Saturation ◽  
Hemoglobin Concentration ◽  
Step Test ◽  
Arterial Oxygen ◽  
Spleen Volume ◽  
Spleen Contraction ◽  
Response To Exercise ◽  
Rest And Exercise

Abstract Purpose Hypoxia and exercise are known to separately trigger spleen contraction, leading to release of stored erythrocytes. We studied spleen volume and hemoglobin concentration (Hb) during rest and exercise at three altitudes. Methods Eleven healthy lowlanders did a 5-min modified Harvard step test at 1370, 3700 and 4200 m altitude. Spleen volume was measured via ultrasonic imaging and capillary Hb with Hemocue during rest and after the step test, and arterial oxygen saturation (SaO2), heart rate (HR), expiratory CO2 (ETCO2) and respiratory rate (RR) across the test. Results Resting spleen volume was reduced with increasing altitude and further reduced with exercise at all altitudes. Mean (SE) baseline spleen volume at 1370 m was 252 (20) mL and after exercise, it was 199 (15) mL (P < 0.01). At 3700 m, baseline spleen volume was 231 (22) mL and after exercise 166 (12) mL (P < 0.05). At 4200 m baseline volume was 210 (23) mL and after exercise 172 (20) mL (P < 0.05). After 10 min, spleen volume increased to baseline at all altitudes (NS). Baseline Hb increased with altitude from 138.9 (6.1) g/L at 1370 m, to 141.2 (4.1) at 3700 m and 152.4 (4.0) at 4200 m (P < 0.01). At all altitudes Hb increased from baseline during exercise to 146.8 (5.7) g/L at 1370 m, 150.4 (3.8) g/L at 3700 m and 157.3 (3.8) g/L at 4200 m (all P < 0.05 from baseline). Hb had returned to baseline after 10 min rest at all altitudes (NS). The spleen-derived Hb elevation during exercise was smaller at 4200 m compared to 3700 m (P < 0.05). Cardiorespiratory variables were also affected by altitude during both rest and exercise. Conclusions The spleen contracts and mobilizes stored red blood cells during rest at high altitude and contracts further during exercise, to increase oxygen delivery to tissues during acute hypoxia. The attenuated Hb response to exercise at the highest altitude is likely due to the greater recruitment of the spleen reserve during rest, and that maximal spleen contraction is reached with exercise.

Decline in peripheral chemoreceptor excitatory stimulation during acute hypoxia in the lamb

1987 ◽  
Vol 63 (2) ◽  
pp. 795-802 ◽  
Author(s):  
J. L. Carroll ◽  
M. A. Bureau
Keyword(s):  
Acute Hypoxia ◽  
Peripheral Chemoreceptor

Chemoreceptor function was studied in eight 2- to 3-day-old unanesthetized lambs to sequentially assess hypoxic chemoreflex strength during an 18-min exposure to hypoxia [inspired O2 fraction (FIO2) = 0.08]. The immediate ventilatory (VE) drop in response to five breaths of pure O2 was measured at 3, 7, and 15 min during hypoxia. Each lamb was studied again at 10–11 days of age. At 2–3 days of age VE increased, with the onset of hypoxia, from 658 +/- 133 (SD) ml.min-1 X kg-1 to a peak of 1,124 +/- 177 ml.min-1 X kg-1. A dampening of the VE response then occurred, with a mean decline in VE of 319 ml.min-1 X kg-1 over the 18-min hypoxia period. Each pure O2 test (Dejours test) resulted in an abrupt fall in VE (delta VEDejours). This VE drop was 937 +/- 163, 868 +/- 244, and 707 +/- 120 ml.min-1 X kg-1 at 3, 7, and 15 min of hypoxia, respectively. Comparing the three O2 tests, delta VEDejours was significantly decreased by 15 min, indicating a loss of about one-fourth of the O2 chemoreflex drive during hypoxia. Testing at 10–11 days of age revealed a smaller VE decline during hypoxia. O2 tests at the beginning and end of the hypoxic period were not significantly different, indicating a smaller loss of hypoxic chemoreflex drive in the more mature animals.(ABSTRACT TRUNCATED AT 250 WORDS)

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