Stroke, Vol 7, 469-472, Copyright © 1976 by American Heart Association
HI Bicher and P Marvin
The effect of several agents active on autonomic nervous system functions
was tested on brain oxygen autoregulation parameters. It was found that
atropine, propranolol and isoproterenol had no influence in abolishing the
measured parameters. Phenoxybenzamine, tolazoline and dibenamine all
suppress autoregulation. In an additional experimental series, a
phenoxybenzamine infusion was given during O2 breathing. The infusion
induced, in most cases, an additional rise in TpO2 (tissue pressure of
oxygen, which refers to the partial pressure [in mm Hg] of this gas at the
measuring tip of the electrode). It is concluded that an alpha-adrenergic
mechanism is part of the autoregulation process. Also, the increase in
brain TpO2 induced by 59% O2-5% Co2 breathing seems to be blocked or
reversed by alpha-adrenolytic drugs, thus supporting the thinking that the
effect of CO2 on cerebral blood flow is at least in part mediated through
an alpha-adrenergic response.
ARTICLES
Pharmacological control of local oxygen regulation mechanisms in brain tissue
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