AJP - Regulatory, Integrative and Comparative Physiology, Vol 257, Issue 6 1365-R1369, Copyright © 1989 by American Physiological Society
Effect of atriopeptin on blood flow to cerebrum and choroid plexus
K. A. Schalk, J. L. Williams and D. D. Heistad
Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242.
The goal of this study was to determine whether atriopeptin alters blood
flow to cerebrum and choroid plexus. In anesthetized rabbits, blood flow
(microspheres) to cerebrum and choroid plexus under control conditions was
36 +/- 3 (mean +/- SE) and 573 +/- 78 ml.min-1.100 g-1, respectively.
Infusion of atriopeptin (75, 225, 1,150 ng.kg-1.min-1 iv) increased blood
flow to choroid plexus by 22 +/- 11, 53 +/- 26, and 51 +/- 13%,
respectively. In contrast, blood flow to cerebrum was not altered by
atriopeptin, presumably because the blood-brain barrier prevented access to
cerebral vascular smooth muscle. Because a major role of atriopeptin may be
to modulate responses to angiotensin II, we examined effects of atriopeptin
on vasoconstrictor responses to angiotensin II in the choroid plexus.
Angiotensin II was infused in the presence or absence of atriopeptin (300
ng.kg-1.min-1 iv). Angiotensin II (100 ng.kg-1.min-1 iv) decreased blood
flow to choroid plexus by 49 +/- 12% and by 47 +/- 14% during simultaneous
infusion of atriopeptin. In summary, atriopeptin 1) increases blood flow to
choroid plexus, but not cerebrum, and 2) does not appear to attenuate
vasoconstrictor effects of angiotensin II in the choroid plexus.
