Effect of dietary zinc deficiency on brain metallothionein-I and -III mRNA levels during stress and inflammation (original) (raw)

Zinc is an essential heavy metal for the normal function of the central nervous system (CNS), but the knowledge of its metabolism and functions is scarce. In this report we have studied the eect of a zinc de®cient diet on the regulation of brain metallothioneins (MTs). In situ hybridization analysis revealed that brain MT-I induction by restraint stress was signi®cantly blunted in some but not all brain areas in the mice fed the zinc de®cient diet compared to normally fed mice. In contrast, brain MT-I induction by the administration of bacterial lipopolysaccharide (LPS) was not signi®cantly lower in the mice fed the zinc de®cient diet. In contrast to MT-I, MT-III mRNA levels were minimally aected by either stress or LPS. Yet, signi®cant decreasing eects of the zinc de®cient diet were observed in areas such as the neocortex, CA1±CA3 neuronal layer and dentate gyrus of the hippocampus, and the Purkinje neuronal layer of the cerebellum. These results demonstrate that dietary zinc de®ciency impairs the response of brain MTs during both stress and LPS-elicited in¯ammatory response in a highly speci®c manner.