Research Article

Clinical usefulness of urinary 3-methylhistidine excretion in indicating muscle protein breakdown.

Br Med J (Clin Res Ed) 1981; 282 doi: https://doi.org/10.1136/bmj.282.6261.351 (Published 31 January 1981) Cite this as: Br Med J (Clin Res Ed) 1981;282:351
  1. M Elia,
  2. A Carter,
  3. S Bacon,
  4. C G Winearls,
  5. R Smith

    Abstract

    Urinary excretion of the post-translationally modified amino-acid 3-methylhistidine, derived from the contractile proteins actin and myosin, was measured in patients with conditions associated with nitrogen loss. The ratio of 3-methylhistidine:creatinine excretion, a measure of the fractional catabolic rate of myofibrillar protein was increased in severe injury, thyrotoxicosis, neoplastic disease, prednisolone administration, and sometimes Duchenne muscular dystrophy. In myxoedema, osteomalacia, and hypothermia the ratio was decreased; and starvation, elective operations, and rheumatoid arthritis had little effect. Provided that the diet is meat free, measurement of urinary 3-methylhistidine may provide useful information on the cause of protein loss.