Calorimetry and respirometry in guinea pigs in hydrox and heliox at 10–60 atm

Fahlman, Andreas; Kaveeshwar, Jaya A.; Tikuisis, Peter; Kayar, Susan R.

doi:10.1007/s004240000385

Cited by 3 publications

(1 citation statement)

References 23 publications

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“…It can be expected that the animal would not lose any heat by evaporation (h e) from the body surface when submerged (22). In addition, the respiratory heat loss (hr) has been estimated to be negligible compared with the total heat loss in air in small mammals (18) and in Adélie penguins (8). Therefore, the respiratory and evaporative heat transfer rates were assumed to be negligible in the water channel (h rϩe ϭ 0).…”

Section: Heat Lossmentioning

confidence: 99%

Metabolism and thermoregulation during fasting in king penguins,Aptenodytes patagonicus,in air and water

Fahlman

Schmidt²,

Handrich³

et al. 2005

American Journal of Physiology-Regulatory, Integrative and Comp

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We measured oxygen consumption rate (V O2) and body temperatures in 10 king penguins in air and water. V O2 was measured during rest and at submaximal and maximal exercise before (fed) and after (fasted) an average fasting duration of 14.4 Ϯ 2.3 days (mean Ϯ 1 SD, range 10 -19 days) in air and water. Concurrently, we measured subcutaneous temperature and temperature of the upper (heart and liver), middle (stomach) and lower (intestine) abdomen. The mean body mass (M b) was 13.8 Ϯ 1.2 kg in fed and 11.0 Ϯ 0.6 kg in fasted birds. After fasting, resting V O2 was 93% higher in water than in air (air: 86.9 Ϯ 8.8 ml/min; water: 167.3 Ϯ 36.7 ml/min, P Ͻ 0.01), while there was no difference in resting V O2 between air and water in fed animals (air: 117.1 Ϯ 20.0 ml O 2/min; water: 114.8 Ϯ 32.7 ml O2/min, P Ͼ 0.6). In air, V O2 decreased with Mb, while it increased with Mb in water. Body temperature did not change with fasting in air, whereas in water, there were complex changes in the peripheral body temperatures. These latter changes may, therefore, be indicative of a loss in body insulation and of variations in peripheral perfusion. Four animals were given a single meal after fasting and the temperature changes were partly reversed 24 h after refeeding in all body regions except the subcutaneous, indicating a rapid reversal to a prefasting state where body heat loss is minimal. The data emphasize the importance in considering nutritional status when studying king penguins and that the fasting-related physiological changes diverge in air and water. thermoregulatory plasticity; hypometabolism; sea bird; allometry THE USE OF HEART RATE (f H ) as an indicator of the oxygen consumption rate (V O 2 ) has previously been used to estimate field metabolic rate in king penguins both on land and in water (21). Unfortunately, the relationship between f H and V O 2 for a given species does not necessarily remain constant throughout the life history. The relationship has been shown to vary with the type of activity (7, 43), physiological state (fasting, breeding; 17, 20), and with season (28). Whereas the relationship was shown to be similar in air and water in gentoo (3) and macaroni penguins (24), the use of f H to predict V O 2 in other penguin species requires validation studies to be performed both in water and on land.Before attempting to estimate the relationship between f H and V O 2 in king penguins in water, we considered it crucial first to study the complex body temperature changes (thermoregulatory plasticity) reported in this species (26). This is important for two reasons. First, we previously measured a significant reduction in V O 2 during fasting in air and hypothesized that this was in part due to a change in the body temperature of the birds (17). This observation prompted us to try to determine whether similar changes occur in king penguins while fasting in water. Secondly, as V O 2 decreases during fasting in air, a rapid reversal of this reduction after refeeding would be indicative of physiological or biochem...

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Section: Heat Lossmentioning

confidence: 99%

Metabolism and thermoregulation during fasting in king penguins,Aptenodytes patagonicus,in air and water

Fahlman

Schmidt²,

Handrich³

et al. 2005

American Journal of Physiology-Regulatory, Integrative and Comp

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Hydrogen: From Stars to Fuel to Medicine

LeBaron,

Sharpe,

Pyatakovich

et al. 2024

Advances in Biochemistry in Health and Disease

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The On/Off History of Hydrogen in Medicine: Will the Interest Persist This Time Around?

LeBaron

Ohno

Hancock

2023

Oxygen

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Over 2000 publications including more than 100 human studies seem to indicate that humans have only recently benefited from or known about the medical effects of H2 within the past 15 years. However, we have unknowingly benefited from H2 since the dawn of time, from H2-producing bacteria to the use of naturally occurring hydrogen-rich waters. Moreover, the first writings on the therapeutic effects of H2 date to around 1793. Since then, papers appeared sporadically in the literature every few decades but never exploded until Ohsawa et al. again demonstrated hydrogen’s therapeutic effects in 2007. This landmark paper appears to have been the spark that ignited the medical interest in hydrogen. Although H2 was used in the 1880s to locate intestinal perforations, in the 1940s in deep sea diving, and in the 1960s to measure blood flow, H2 was largely viewed as biologically inert. This review highlights the history of hydrogen in the genesis/evolution of life and its medicinal and non-medicinal use in humans. Although hydrogen medicine has a long and erratic history, perhaps future history will show that, this time around, these 15 years of ignited interest resulted in a self-sustaining explosion of its unique medical effects.

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Calorimetry and respirometry in guinea pigs in hydrox and heliox at 10–60 atm

Cited by 3 publications

References 23 publications

Metabolism and thermoregulation during fasting in king penguins,Aptenodytes patagonicus,in air and water

Metabolism and thermoregulation during fasting in king penguins,Aptenodytes patagonicus,in air and water

Hydrogen: From Stars to Fuel to Medicine

The On/Off History of Hydrogen in Medicine: Will the Interest Persist This Time Around?

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