Seasonal Variation in Human Amino Acid Excretion,
SCHOOL OF AVIATION MEDICINE RANDOLPH AFB TEX
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Amino acid excretion was studied in young, healthy men during summer, fall, and winter months in a location in southwestern United States. Both random and timed urine samples were employed. The amino acids determined were alanine, arginine, cysteine, glutaminetaminetaminetamic acid, glu glycine, histidine, lysine, methyl histidine, serine, threonine, and valine. Supplemental determinations included urine volume, creatinine, uric acid, urea, sodium, and potassium. Using random samples, and expressing values as ratios with creatinine, significant seasonal variation was found for alanine, arginine, cysteine, glutamic acid, glycine, lycine, serine, urea, and uric acid. Although there was no significant variation in urine volume, both creatinine excretion and the urinary NaK ratio varied significantly with season. These effects are interpreted as the result of changes in glomerular filtration and tubular reabsorption rates.
- Anatomy and Physiology