NEURONAL LOCALIZATION OF METALLOTHIONEIN IN RAT AND HUMAN SPINAL-CORD

The immunocytochemical localization of the metallothioneins (MT), a fa mily of low molecular weight, heavy metal binding proteins, was invest igated in rat and human spinal cord using two distinct antibodies. Pol yclonal antibodies were raised to the peptide (SCKCKECKCTS), an epitop e common to all human MT isoforms. The monoclonal antibody, E9 which r ecognizes a different epitope of the MT protein, was also used. Simila r results were obtained with either antibody. Both antibodies recogniz ed authentic MT from rabbit liver and horse kidney on Western blots. I mmunoreactivity was localized primarily in the cytoplasm of motoneuron s in the anterior horn of cervical and lumbar cord. However nuclear st aining was present in some motoneurons in both rat and human cord. Int ense nuclear, as well as cytoplasmic staining was seen in astrocytes. Capillary endothelia, ependymal cells, arachnoid and pia were also pos itive for MT.