Thermal sweat lactate in cystic fibrosis and in normal children.
We attempt to determine whether the decrease in Na+ reabsorption and the increase in K+ secretion in sweat of cystic fibrosis patients (CF) were associated with changes in glandular anaerobic metabolism evaluated by forehead sweat lactate excretion rate. 6 CF and 11 normal (C) children, 5 months to 14 years old, were exposed to external thermal load (45 degrees C). The data showed that: 1) Na+, K+ and Cl- concentrations in CF are constant at any flow rate (Qsw); 2) In both groups the excretion rates of Na+, K+ and Cl- increased linearly with Qsw but the slopes in CF were significantly higher than in C (p less than 0.001); 3) Lactate excretion rate increased with Qsw as in CF and C with the same slope. We suggest that an increase in energy expenditure of Na+ - K+ exchange and an active secretion of K+ by the duct could explain the normal energy metabolism that we observed in CF sweat glands.
D002648:Child; D002675:Child, Preschool; D002712:Chlorides / Q000378:metabolism; D003550:Cystic Fibrosis / Q000378:metabolism*; D004734:Energy Metabolism; D006358:Hot Temperature; D006801:Humans; D007223:Infant; D007773:Lactates / Q000378:metabolism*; D019344:Lactic Acid; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013542:Sweat / Q000378:metabolism*; D013546:Sweating
D002712:Chlorides; D007773:Lactates; D019344:Lactic Acid; D012964:Sodium; D011188:Potassium