[Influence of a central cholinergic mode of action on the regulation of the intact and disturbed cerebral blood flow (author's transl)].
Cerebral chemical vasomotor reactivity and autoregulation were tested in normal baboons before and after intravertebral, intravenous and (or) intracarotid infusion of atropine and neostigmine. Furthermore, disordered cholinergic neurotransmission and dysautoregulation after acute experimental cerebral infarction have also been investigated. Intravertebral injection of atropine suppressed the increase of CBF by inhalation of 5% CO2 and enhanced the decrease of CBF induced by hyperventilation, but did not appreciably affect autoregulatory response. On the other hand, cerebral autoregulatory vasoconstriction during increases of CPP was significantly reduced following both intravertebral and intracarotid neostigmine infusion. Cerebral vasodilatory reactivity to CO2 inhalation was significantly enhanced only following intravertebral neostigmine and cerebral vasoconstrictive response to hyperventilation was not influenced by neostigmine. Following experimental cerebral infarction regional dysautoregulation was found in infarcted gray matter and correlated significantly with increased AChE levels in the same zones of cortex and basal ganglia. Intravenous infusion of scopolamine restored autoregulation to the ischemic zones. The results thus obtained support the view that central cholinergic cerebrovascular influences exist and are vasodilatory in nature. Furthermore, in acute experimental cerebral infarction disordered cholinergic neurotransmission seems to play a role in vasoconstrictive dysautoregulation.