Logalization of metallothionein in the brain of macaca fascicularis.

Abstract

The localization of metallothionein (MT), a heavy metal binding protein of low molecular weight, in the brain of young and old macaca fascicularis was investigated by immunohistochemical technique, and the amounts of MT and heavy metals (Zn, Cu, Cd) were measured by radioimmunoassay and atomic absorption spectrophotometer, respectively. Immunohistochemically, MT was found in pia mater, ependymal cells, protoplasmic astrocytes of the gray matter and fibrous astrocytes of the white matter of cerebrum. Cytoplasm and processes of protoplasmic and fibrous astrocytes showed strong MT immunostaining. Also, vascular feet and adventitia gave positive MT immunostaining. Moreover, both protoplasmic and fibrous astrocytes in pons and spinal cord showed the same positive MT immunostaining as those in cerebrum. In the cerebellum, Bergmann's glias, protoplasmic astrocytes of granular layer and nucleus dentatus, and fibrous astrocytes of white matter showed a strongly positive immunostain for MT.According to the radioimmunoassay, the amount of MT in the brain of the old one was relatively high-about 19.3 μg/g wet weight. For the heavy metals in the brain, zinc and copper were detected, excepting cadmium.