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Effects of potassium intake on potassium, sodium and fluid balance in exercising horses
Author(s) -
JANSSON ANNA,
LINDHOLM A.,
LINDBERG J. E.,
DAHLBORN KRISTINA
Publication year - 1999
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/j.2042-3306.1999.tb05257.x
Subject(s) - excretion , potassium , sodium , endocrinology , medicine , chemistry , urine , fluid intake , horse , zoology , sweat , biology , paleontology , organic chemistry
Summary The aim of this study was to investigate the adaptation to an increased potassium (K + ) intake in horses and to study whether the regulation of the post exercise K + , sodium (Na + ) and fluid balances were altered by an increased K + intake. Four Standardbred horses were fed 2 levels (4.1 and 5.4 mmol/kg bwt/day) of K + for 17 days in a crossover design. The effects on K + , Na + and fluid balance were studied both at rest and in response to 29 km exercise. K + , Na + and fluid intakes and outputs were balanced within 24 h after a new diet had been introduced. Adaptation consisted primarily of an increased urinary K + excretion, later followed by an increase in faecal excretion. The increased urinary K + excretion was associated with an increased mass of urine (1.2–1.4 kg/day) compensated for by an increased water intake. The sweat Na + concentration was increased on the highest K + intake (from 123 ± 5 mmol/l to 138 ± 3 mmol/l) and the urinary Na + excretion was lower post exercise on this diet. There were no differences in the magnitude of post exercise hypokalaemia between the diets, and plasma K + concentration was still reduced 24 h post exercise even when the horses were fed the higher K + diet. Adaptation to an increased K + intake was rapid in these horses and consisted mainly of an increased urinary excretion. The response to exercise was unaltered by the increased K + intake, except for an increased Na + concentration in sweat.