Skeletal muscle injury after magnesium depletion in the dog

Abstract

Magnesium deficiency was induced in a setting of an otherwise adequate diet in adult beagle dogs. Despite the development of severe hypomagnesemia (from 1.5 +/- 0.2 to 0.5 +/- 0.2 meq/liter) during the 10-wk study, Mg content of skeletal muscle fell only modestly (from 3.8 +/- 0.2 to 3.1 +/- 0.4, P less than 0.005, at 7 wk and 3.5 +/- 0.4 mM/100 g FFDS, NS, at 10 wk). The most pronounced muscle compositional changes were a loss of phosphorus (from 29.5 +/- 1.8 to 22.0 +/- 1.6, P less than 0.001, at 7 wk and 24.8 +/- 2.8 mM/100 G FFDS, P less than 0.001, at 10 wk) and gains of calcium (from 0.64 +/- 0.11 to 0.93 +/- 0.17, P less than 0.05, at 7 wk, and 0.85 +/- 0.26 mM/100 g FFDS, P less than 0.05, at 10 wk), sodium (from 13.2 +/- 2.6 to 22.9 +/- 4.7, P less than 0.001 at 7 wk and 17.8 +/- 2.0 meq/100 g FFDS, P less than 0.005, at 10 wk), and chloride (from 5.8 +/- 0.8 to 8.2 +/- 1.6, P less than 0.001, at 7 wk and 6.8 +/- 0.6 meq/100 g FFDS, P less than 0.05, at 10 wk). Cellular potassium content did not change (from 35.9 +/- 1.9 to 33.0 +/- 4.1, NS, at 7 wk and 36.3 +/- 2.0 meq/100 g FFDS, NS, at 10 wk). Muscle cell electrical hyperpolarization developed after 10 wk of Mg depletion. Convulsive seizures developed in three animals. Frank rhabdomyolysis in three animals and focal necrosis in four animals were present on terminal biopsy, with only four animals having completely normal histology.

Role of cellular magnesium in health and human disease

“…A study of magnesium supplementation in animals with oxidative stress diseases suggested its anti-peroxidant effect through a finding of decreased lipid peroxidation (81). Magnesium-deficient animals showed, among other pathological signs, anemia (82), myopathy (83), muscular weakness (84), tetany (16), cardiac rhythm disorders, and changes in blood pressure (85). These data should be treated with care in application to humans, since they were observed in severely magnesium-deficient animals.…”

Elevated serum manganese concentration in dogs as a possible predisposing factor of cerebral babesiosis in dogs

“…Furthermore, the differences in electrolyte levels between the different study groups were not significant enough to allow the assumption that they might have been a trigger for neurological signs in dogs in Group 2. Neurological signs in dogs may be the consequence of a reduced serum Mg concentration (Cronin et al, 1982), but in all animals used in the study, serum Mg was within the physiological limits. On this basis, it was assumed that an increased concentration of Mn could have had an impact on the occurrence of neurological disorders.…”