Endothelin‐like immunoreactivity is expressed in reactive astrocytes in cases of cerebral infarcts and lacunes

Abstract

The avidin-biotin peroxidase complex method and a polyclonal antiserum were used to investigate the expression of endothelin-like immunoreactivity in human autopsy cases presenting cerebral infarcts and lacunes. Cases with recent infarcts showed loss of immunoreactivity in neurons of the infarcts. Immunoreactive granules started to appear in astrocytic endfeet of microvessels of the border zones. Later on, numerous reactive astrocytes presented immunoreactivity in the entire cell body. Cases with old infarcts had a more widespread presence of astrocytes with endothelin-like immunoreactivity around the lesions. Macrophages particularly of old infarcts showed a strong immunoreactivity. Cases with old lacunes presented numerous reactive fibrillary astrocytes with endothelin-like immunoreactivity in the cell body and the processes. Astrocytes of controls showing endothelin-like immunoreactivity were very rare and such cells were usually confined to the molecular layer of the cerebral cortex. The endothelin-like immunoreactivity in astrocytes and macrophages of cases with cerebrovascular diseases probably reflects an increased intracellular content of endothelin. If this compound is released from such cells it may act as a mitogen and influence microcirculation by inducing vasoconstriction of intracerebral arterioles.-