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The relation between blood lactate and ammonia in ischemic handgrip exercise
Author(s) -
Sinkeler Sytze P. T.,
Daanen Hein A. M.,
Wevers Ron A.,
Oei T. Lian,
Joosten Ed M. G.,
Binkhorst Rob A.
Publication year - 1985
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880080608
Subject(s) - isometric exercise , blood lactate , medicine , cardiology , physical exercise , physical therapy , anesthesia , endocrinology , heart rate , blood pressure
Subjects with myopathies associated with certain enzyme defects often show abnormal concentrations of lactate (LA) and ammonia (NH 3 ) in blood after ischemic exercise. Myoadenylate deaminase (MAD) deficient patients produce only small amounts of NH 3 , whereas LA rises to normal levels. On the other hand, patients with certain enzyme deficiencies in the glyco(geno)lytic pathway show the opposite. However, the concentrations in blood are dependent on the exercise performed. Standardization of tests for screening purposes, therefore, is necessary. For ischemic contractions, experiments were performed to find the optimal combination for force and frequency, using the highest LA and NH 3 concentrations in blood as criteria. Eleven healthy subjects performed ischemic isometric contractions with a handgrip dynamometer at frequencies of 30 and 50/min −1 and force levels of 50%, 65%, and 80% of maximal voluntary contraction (MVC). A combination of 30/min −1 and 80% MVC was found to give the best results.