IMMUNOHISTOCHEMICAL DEMONSTRATION OF TISSUE KALLIKREIN IN THE NEURONSOF RAT-BRAIN

The distribution of tissue kallikrein (EC.3.4.21.35) in the rat brain was investigated by an enzyme-linked immunosorbent assay (ELISA) and i mmunohistochemical technique using antiserum against rat urinary kalli krein. More than 75% of the total amount of kallikrein in the extracts of the cerebral cortex and brain stem was determined by the ELISA to be in the form of prokallikrein, suggesting that the greater part of t he enzyme exists in the form of pro-enzyme in the central nervous syst em. Furthermore, immunohistochemical examination revealed that, althou gh the kallikrein-positive cells were widespread and scattered in the brain, the immunoreactive substances preferentially locate in the neur onal cell bodies and their processes in both the cerebral cortex and b rainstem.