Features of Central Neurotransmission in Animals in Conditions of Dietary Magnesium Deficiency and After Its Correction

Abstract

Magnesium is important in the regulation of neurotransmitter metabolism and the modulation of receptor function in the CNS, including neurotransmitters and receptors involved in the pathogenesis of many mental disorders. The aim of the present work was to perform a pharmacological evaluation of the central mechanisms of action of magnesium salts in the clofelin, phenamine, arecoline, nicotine, apomorphine, and 5-hydroxytryptophan tests in conditions of dietary magnesium deficiency. After reaching the magnesium deficiency state, animals were given oral (via tube) magnesium L-asparaginate and magnesium chloride lone and in combination with vitamin B(6), as well as the reference agent Magne B6. Our assessments of phenamine stereotypy in magnesium-deficient animals showed reductions in the latent period by an average of 14.89% and a significant increase in the duration of phenamine stereotypy by an average of 19.44% (from 268.23 +/- 8.17 to 320.36 +/- 19.90 min) as compared with intact rats. Studies of hyperkinesia induced by 5-hydroxytryptophan showed a two-fold reduction in its extent in the magnesium-deficient group (p </= 0.05). Administration of arecoline to magnesium-deficient animals resulted in a statistically significant increase in the latent period from a mean of 92.75 +/- 19.35 to 245.17 +/- 121.86 sec, with a reduction in the duration of tremor from an average of 1175.58 +/- 127.87 to 703.83 +/- 89.33 sec (p </= 0.05) as compared with intact rats. In terms of its influence on the hypothermic effects of clofelin and apomorphine and the convulsive effect of nicotine, there were no significant differences between the intact group and the magnesium-deficiency animals. Administration of magnesium salts compensated for the magnesium deficiency in plasma and erythrocytes, which was accompanied by recovery of measures in the phenamine, arecoline, and 5-HT tests to levels typical of intact controls. There was a tendency for magnesium L-asparaginate and magnesium chloride combined with pyridoxine to have greater activity, and the efficacies of these treatments was no less than that of reference agent Magne B6. Thus, dietary magnesium deficiency led to impairment of neurotransmission in central serotoninergic, M-cholinergic, and noradrenergic structures and administration of magnesium salts reversed these changes.