Sweat ammonia excretion during submaximal cycling exercise

Czarnowski, D.; Górski, Jan

doi:10.1152/jappl.1991.70.1.371

“…The overall sweat Lac -of the boys (16.6 mM) and men (15.1 mM) in the present study agrees with those reported for boys (7) and men (6,11,18) performing similar exercise protocols. The mean sweat Lac -of women (14.3 mM) in the present study, however, was much lower than that of sedentary (100 mM) or fit (43 mM) women (8).…”

Section: Discussionsupporting

confidence: 91%

“…In the present study, the men's average sweat NH 3 (3.3 mM) was somewhat higher than that found when men cycled at 40% (2.1 mM), but much lower than that obtained at a higher exercise intensity (7.1 mM at 80% VO 2max ) (6). This further indicates that sweat NH 3 increases with exercise intensity.…”

Section: F Meyer Et Alcontrasting

confidence: 68%

Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat

Meyer¹,

Laitano²,

Bar-Or³

et al. 2007

Braz J Med Biol Res

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The dependence of sweat composition and acidity on sweating rate (SR) suggests that the lower SR in children compared to adults may be accompanied by a higher level of sweat lactate (Lac -) and ammonia (NH 3 ) and a lower sweat pH. Four groups (15 girls, 18 boys, 8 women, 8 men) cycled in the heat (42ºC, 20% relative humidity) at 50% VO 2max for two 20-min bouts with a 10-min rest before bout 1 and between bouts. Sweat was collected into plastic bags attached to the subject's lower back. During bout 1, sweat from girls and boys had higher Lac -concentrations (23.6 ± 1.2 and 21.2 ± 1.7 mM; P < 0.05) than sweat from women and men (18.2 ± 1.9 and 14.8 ± 1.6 mM, respectively), but Lac -was weakly associated with SR (P > 0.05; r = -0.27). Sweat Lac -concentration dropped during exercise bout 2, reaching similar levels among all groups (overall mean = 13.7 ± 0.4 mM). Children had a higher sweat NH 3 than adults during bout 1 (girls = 4.2 ± 0.4, boys = 4.6 ± 0.6, women = 2.7 ± 0.2, and men = 3.0 ± 0.2 mM; P < 0.05). This difference persisted through bout 2 only in females. On average, children's sweat pH was lower than that of adults (mean ± SEM, girls = 5.4 ± 0.2, boys = 5.0 ± 0.1, women = 6.2 ± 0.5, and men = 6.2 ± 0.4 for bout 1, and girls = 5.4 ± 0.2, boys = 6.5 ± 0.5, women = 5.2 ± 0.2, and men = 6.9 ± 0.4 for bout 2). This may have favored NH 3 transport from plasma to sweat as accounted for by a significant correlation between sweat NH 3 and H + (r = 0.56). Blood pH increased from rest (mean ± SEM; 7.3 ± 0.02) to the end of exercise (7.4 ± 0.01) without differences among groups. These results, however, are representative of sweat induced by moderate exercise in the absence of acidosis.

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“…24,61,62 Ammonia is also of interest because it is a possible and needed substitute for lactate measurement of anaerobic condition (see Subsection IV H). Ammonia (NH 3 ) passes through the cells lining the secretory coil by means of a passive diffusive mechanism.…”

Section: Weak Acid or Base Partitioning Which Is Passive But Amplimentioning

confidence: 99%

“…More details can be found elsewhere. 23,61,62,64 Regardless, this protonation of ammonia is practically beneficial as it increases the concentration, which potentially simplifies sensor detection methods. 10 Ammonia is one example of many possible examples of molecules which could permeate the epithelial membrane of the eccrine sweat gland via diffusion and become entrapped within the lumen due to ionization.…”

Section: Weak Acid or Base Partitioning Which Is Passive But Amplimentioning

confidence: 99%

The microfluidics of the eccrine sweat gland, including biomarker partitioning, transport, and biosensing implications

Sonner

¹

,

Wilder

²

,

Heikenfeld

³

et al. 2015

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Non-invasive and accurate access of biomarkers remains a holy grail of the biomedical community. Human eccrine sweat is a surprisingly biomarker-rich fluid which is gaining increasing attention. This is especially true in applications of continuous bio-monitoring where other biofluids prove more challenging, if not impossible. However, much confusion on the topic exists as the microfluidics of the eccrine sweat gland has never been comprehensively presented and models of biomarker partitioning into sweat are either underdeveloped and/or highly scattered across literature. Reported here are microfluidic models for eccrine sweat generation and flow which are coupled with review of blood-to-sweat biomarker partition pathways, therefore providing insights such as how biomarker concentration changes with sweat flow rate. Additionally, it is shown that both flow rate and biomarker diffusion determine the effective sampling rate of biomarkers at the skin surface (chronological resolution). The discussion covers a broad class of biomarkers including ions (Na(+), Cl(-), K(+), NH4 (+)), small molecules (ethanol, cortisol, urea, and lactate), and even peptides or small proteins (neuropeptides and cytokines). The models are not meant to be exhaustive for all biomarkers, yet collectively serve as a foundational guide for further development of sweat-based diagnostics and for those beginning exploration of new biomarker opportunities in sweat.

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“…The Lac -in sweat is derived mainly from anaerobic glycolysis within the sweat glands (2)(3)(4). The high sweat NH 3 may originate F. Meyer et al from the sweat gland itself or by diffusion from plasma (1,5,6).…”

Section: Introductionmentioning

confidence: 99%

Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat

Meyer

¹

,

Laitano

²

,

Bar‐Or

³

et al. 2007

Braz J Med Biol Res

View full text Add to dashboard Cite

The dependence of sweat composition and acidity on sweating rate (SR) suggests that the lower SR in children compared to adults may be accompanied by a higher level of sweat lactate (Lac -) and ammonia (NH 3 ) and a lower sweat pH. Four groups (15 girls, 18 boys, 8 women, 8 men) cycled in the heat (42ºC, 20% relative humidity) at 50% VO 2max for two 20-min bouts with a 10-min rest before bout 1 and between bouts. Sweat was collected into plastic bags attached to the subject's lower back. During bout 1, sweat from girls and boys had higher Lac -concentrations (23.6 ± 1.2 and 21.2 ± 1.7 mM; P < 0.05) than sweat from women and men (18.2 ± 1.9 and 14.8 ± 1.6 mM, respectively), but Lac -was weakly associated with SR (P > 0.05; r = -0.27). Sweat Lac -concentration dropped during exercise bout 2, reaching similar levels among all groups (overall mean = 13.7 ± 0.4 mM). Children had a higher sweat NH 3 than adults during bout 1 (girls = 4.2 ± 0.4, boys = 4.6 ± 0.6, women = 2.7 ± 0.2, and men = 3.0 ± 0.2 mM; P < 0.05). This difference persisted through bout 2 only in females. On average, children's sweat pH was lower than that of adults (mean ± SEM, girls = 5.4 ± 0.2, boys = 5.0 ± 0.1, women = 6.2 ± 0.5, and men = 6.2 ± 0.4 for bout 1, and girls = 5.4 ± 0.2, boys = 6.5 ± 0.5, women = 5.2 ± 0.2, and men = 6.9 ± 0.4 for bout 2). This may have favored NH 3 transport from plasma to sweat as accounted for by a significant correlation between sweat NH 3 and H + (r = 0.56). Blood pH increased from rest (mean ± SEM; 7.3 ± 0.02) to the end of exercise (7.4 ± 0.01) without differences among groups. These results, however, are representative of sweat induced by moderate exercise in the absence of acidosis.

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Sweat ammonia excretion during submaximal cycling exercise

Cited by 37 publications

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Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat

Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat

The microfluidics of the eccrine sweat gland, including biomarker partitioning, transport, and biosensing implications

Effect of age and gender on sweat lactate and ammonia concentrations during exercise in the heat

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