Abstract
To clarify the effect of thiamine on serotonin metabolism in magnesium deficient rats, in vivo and in vitro experiments were carried out. Six different synthetic diets were given to Wistar rats for two or four weeks. Group I, thiamine and magnesium deficient ; group II, thiamine deficient and magnesium sufficient ; group III, thiamine adequate, magnesium deficient ; group IV, thiamine adequate, magnesium sufficient ; group V, thiamine excess, magnesium deficient ; group VI, thiamine excess, magnesium sufficient. After 10 days on these dietary regimens, rats fed a magnesium deficient diet (groups I, III and V) developed erythema in the ears and nose. However, in rats fed both thiamine and magnesium deficient diet (group I) these symptoms were disappeared at the four week period on regimens. Body temperature decreased markedly in thiamine deficient groups of I and II. Among thiamine sufficient groups, body temperatures were lower in magnesium deficient groups (groups III and V) rather than magnesium sufficient groups (groups II and IV). Serotonin levels in blood and liver increased in groups I, III and V after 2 weeks, but after 4 weeks, serotonin decreased to normal value in group I. Serotonin oxidation activity in liver and stomach decreased significantly in groups II and IV. In vitro addition of a metal chelating agents and either thiamine or thiamine pyrophosphate to brain and liver mitochondria of intact rats resulted in a decrease in serotonin oxidation activities.
