Changes in cerebral vasomotor reactivity to CO2 and autoregulation following experimental subarachnoid hemorrhage

Hashi, Kazuo; Meyer, John Stirling; Shinmaru, S.; Welch, K. M. A.; Teraura, Tetsuaki

doi:10.1016/0022-510x(72)90017-2

Cited by 46 publications

(12 citation statements)

References 9 publications

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“…If there was any change of Paco 2 following inflation or deflation of the balloon, CBF was corrected according to the chemical index previously determined for the baboon. 44 The autoregulation index (A.I.) was measured successfully in nine animals.…”

Section: Methodsmentioning

confidence: 99%

“…To accomplish this, CBF was corrected to the steady state value for CPP by using a formula already determined in the baboon. 44 This formula permits calculation of the expected change in CVR when the perfusion pressure is altered. The formula may be stated as: AF = AP ACVR where AF = the change in CBF and AP = ACPP (calculated from MABPsagittal sinus wedge pressure) between the steady state levels and the level after changing the perfusion pressure.…”

Section: Effects Of Phenoxybenzamine On Cerebral Chemical Vasomotor Rmentioning

confidence: 99%

“…In the above calculations no correction was made for changes of perfusion pressure during HV based on previous experiences in baboons 44 this correction are displayed in table 3B and figure 4. The adjusted decrease of CBF at the end of hyperventilation for five minutes in the PBZ-treated animals was 5.4 ml, a statistically significant reduction in vasoconstrictor response compared to the steady state.…”

Section: Effects Of Phenoxybenzamine On Cerebral Chemical Vasomotor Rmentioning

confidence: 99%

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Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂

Kawamura

Meyer

Hiromoto

et al. 1974

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Abstract• Cerebral autoregulation was studied in the baboon by increasing and decreasing cerebral perfusion pressure (CPP) before and after intravenous administration (1..5 mg per kilogram) of a long-acting alpha adrenergic blocker, phenoxybenzamine (PBZ). Likewise, cerebral vasomotor reactivity to changes of arterial carbon dioxide tension (Paco 2 ) was examined before and after PBZ.In order to permit quantitative analysis, cerebral autoregulation (A.I.) and chemical vasomotor reactivity (C.I.) were expressed as indices whereACPP " ' " ""*• APaco 2 ' Following the intravenous injection of PBZ, cerebral auioregulatory vasoconstriction was impaired as CPP was increased. Cerebral vasomotor reactivity to changes in Paco 2 was altered both during hyperventilation hypocapnia (HV) and hypercarbia induced by inhalation of 5% carbon dioxide if alterations of CPP brought about by these procedures were taken into consideration. During hypocapnia C.I. was reduced 30% and during hypercarbia C.I. was increased 10%.It is concluded that PBZ reduces the vasoconstrictor tonus of cerebral vessels during hypocapnia and raised CPP. It also enhances the vasodilator response to CO, inhalation. Additional Key Words

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Section: Methodsmentioning

confidence: 99%

Section: Effects Of Phenoxybenzamine On Cerebral Chemical Vasomotor Rmentioning

confidence: 99%

Section: Effects Of Phenoxybenzamine On Cerebral Chemical Vasomotor Rmentioning

confidence: 99%

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Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂

Kawamura

Meyer

Hiromoto

et al. 1974

Stroke

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“…Evidence has been presented by Hashi et al 44 and Petruk et al 45 indicating that SAH may impair the autoregulatory mechanisms that maintain a normal CBF in the presence of a changing perfusion pressure. Impaired autoregulation can account in part for the fall in CBF after SAH observed in three of seven monkeys of Group 3 ( fig.…”

Section: Response Of Icp and Mabp To Hypertensive Sah In A Monkey Of mentioning

confidence: 99%

“…In any case, one may postulate that the severe arterial hypertension caused by a sympathetic discharge overwhelms an already partially compromised autoregulatory mechanism. 44 ' 45 The attendant hyperperfusion leads to brain edema, 5153 which is believed to reduce CBF regionally 5456 by increasing brain tissue pressure.…”

Section: Response Of Icp and Mabp To Hypertensive Sah In A Monkey Of mentioning

confidence: 99%

The Effect of a Simulated Subarachnoid Hemorrhage on Cerebral Blood Flow in the Monkey

Martins

Doyle

Newby

et al. 1975

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The hydrogen clearance method was used to measure local and total cerebral blood flow (CBF) in the rhesus monkey before and for five hours after a simulated subarachnoid hemorrhage (SAH). CBF remained stable after SAH unless SAH was associated with a fall in cerebral perfusion pressure. In addition, cerebrovascular resistance did not increase after SAH. These results suggest that vasoactive agents in fresh whole blood, and the arterial spasm they produce when added to cerebrospinal fluid (CSF), play only a limited role in the pathogenesis of ischemic encephalopathy that follows an SAH.

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Vasospasm

Sengupta¹,

McAllister²

1986

Subarachnoid Haemorrhage

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Changes in cerebral vasomotor reactivity to CO2 and autoregulation following experimental subarachnoid hemorrhage

Cited by 46 publications

References 9 publications

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂

The Effect of a Simulated Subarachnoid Hemorrhage on Cerebral Blood Flow in the Monkey

Vasospasm

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Changes in cerebral vasomotor reactivity to CO2 and autoregulation following experimental subarachnoid hemorrhage

Cited by 46 publications

References 9 publications

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO 2

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO 2

The Effect of a Simulated Subarachnoid Hemorrhage on Cerebral Blood Flow in the Monkey

Vasospasm

Contact Info

Product

Resources

About

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂