THE STABILITY OF ANGIOTENSIN RECEPTORS AND ANGIOTENSIN-CONVERTING ENZYME IN POST-MORTEM BRAIN

Quantitative in vitro autoradiography was used to assess the post mort em stability of angiotensin II receptors and angiotensin converting en zyme in adult sheep brainstems. There was no significant loss of angio tensin II receptor binding in brainstems stored for up to 24 h al 23 d egrees C or for 8 h at 23 degrees C followed by 64 h at 4 degrees C. T here was no significant decrease in angiotensin converting enzyme bind ing in the same nuclei after up to 48 h at 23 degrees C or after 8 h a t 23 degrees C followed by up to 64 h at 4 degrees C. Interpretation o f neurochemical studies of human brain tissue obtained at autopsy requ ires assessment of the post mortem stability of the molecules being st udied. Our results indicate that angiotensin II receptors and angioten sin converting enzyme are remarkably stable in sheep brainstems after post mortem delays in excess of those usually encountered in hospital autopsies.