Autoregulation Remains Intact during Stable Xenon Inhalation in the Baboon

  • S. K. WolfsonJr
  • H. Yonas
  • D. Gur
  • E. E. Cook
  • J. Greenberg
  • R. P. Brenner
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 277)


For the measurement of cerebral blood flow (CBF) using the stable xenon/CT method to be recognized as a valuable adjunct to clinical management of ischemic brain syndromes and to both clinical and animal research, it must provide assessment of perfusion reserve. Does blood flow remain under control by metabolic need (autoregulation) or has it become pressure dependent, that is, on the elbow of the autoregulation curve? Usually, resting gray matter flow below 40 to 50 mL/(100 cm3-min) indicates that autoregulation is exceeded or impaired, and levels of 20 to 25 mL/(100 cm3-min) imply exhaustion of reserve with imminent danger of ischemic injury. Since xenon, in concentrations of 30% to 35% as used for clinical CBF determination, is known to alter blood flow with reports of 15% to 20% flow increase toward the end of the 5 min period of Xe breathing, it is important to be certain that autoregulation is not disturbed by the methodology. It has been shown that agents which are known to alter cerebrovascular resistance (CVR) and CBF do not necessarily affect the ability of the brain to regulate flow in the face of varying cerebral perfusion pressure (CPP). Examples are hypocapnea, a potent cerebral vasoconstrictor that does profoundly alter CBF in dogs but does not substantially affect the ability to autoregulate CBF [1], and Mannitol, which improves O2 transport by lowering viscosity but does not raise CBF due to a compensatory elevation in CVR in cats and humans [2,3]. By contrast, the calcium entry blocker, nimodipine, has been shown to impair CBF autoregulation in rats [4].


Cerebral Blood Flow Cerebral Perfusion Pressure Calcium Entry Blocker Cerebral Blood Flow Measurement Alter Blood Flow 
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  1. 1.
    Artru AA, Katz RA, Colley PS. Autoregulation of cerebral blood flow during normocapnia and hypocapnia in dogs. Anesthesiology. 1989; 70:288–292.PubMedCrossRefGoogle Scholar
  2. 2.
    Muizelaar JP, Lutz HA. Becker DP. Effect of mannitol on ICP and CBF and correlation with pressure autoregulation in severely head-injured patients. J. Neurosurg. 1984; 61:700–706.PubMedCrossRefGoogle Scholar
  3. 3.
    Muizelaar JP. Wei EP. Kontos HA. et al. Mannitol causes compensatory cerebral vasoconstriction and vasodilation in response to blood viscosity changes. J. Neurosurg. 1983; 59:822–828.PubMedCrossRefGoogle Scholar
  4. 4.
    Hollerhage HJ. Gaab MR, Zumkeller M, Walter GF. The influence of nimodipine on cerebral blood flow autoregulation and blood-brain barrier. J. Neurosurg. 1988; 69:919–922.PubMedCrossRefGoogle Scholar
  5. 5.
    Drayer BP, Wolfson Jr SK, Reinmuth OM, Dujovny M, Boehkne M, Cook EE. Xenon enhanced computed tomography for the analysis of cerebral integrity, perfusion, and blood flow. Stroke. 1978; 9:123–130.PubMedCrossRefGoogle Scholar
  6. 6.
    Yonas H, Gur D, Claasen D, Wolfson Jr SK, Moossy J. Stable xenon enhanced computed tomography in the study of clinical and pathologic correlates of focal ischemia in baboons. Stroke. 1982; 13:750–758.PubMedCrossRefGoogle Scholar
  7. 7.
    Gur D, Wolfson Jr SK, Yonas H, Good WF, Shabason L, Latchaw RE, Miller DM, Cook EE. Progress in cerebrovascular disease: local cerebral blood flow by xenon enhanced CT. Stroke. 1982; 13:750–758.PubMedCrossRefGoogle Scholar
  8. 8.
    Gur D, Yonas H, Jackson DL, Wolfson Jr SK, Rockette H, Good WF, Cook EE, Arena VC., Willy JA, Maitz GS. Simultaneous measurements of cerebral blood flow by the xenon/CT method and the microsphere method: a comparison. Invest Radiol. 1985a; 20(5):672–677.CrossRefGoogle Scholar
  9. 9.
    Wolfson Jr SK, Clark J, Greenberg JH, Gur D, Yonas H. Brenner RP, Cook EE, Lordeon PA. Simultaneous measurements of normal and low cerebral blood flow states by the Xe/CT method and the [MC]iodoantipyrine method. Submitted for publication.Google Scholar
  10. 10.
    Jasper HH. Report of committee on methods of clinical examination in electroencephalography. Electroencephalogr Clin Neurophysiol. 1958; 10:370–375.CrossRefGoogle Scholar
  11. 11.
    Yonas H, Good WF, Gur D. Wolfson Jr SK, Latchaw RE, Good B, Leanza R, Miller DM. Mapping cerebral blood flow by xenon-enhanced computerized tomography: clinical experience. Radiol. 1984; 19:228–238.Google Scholar

Copyright information

© Plenum Press, New York 1990

Authors and Affiliations

  • S. K. WolfsonJr
    • 1
  • H. Yonas
  • D. Gur
    • 2
  • E. E. Cook
    • 1
  • J. Greenberg
    • 3
  • R. P. Brenner
    • 4
  1. 1.Surgical Research Laboratorym, Montefiore HospitalUniversity of PittsburghUSA
  2. 2.Departments of Neurological Surgery and RadiologyUniversity of PittsburghUSA
  3. 3.Department of NeurologyUniversity of PennsylvaniaPhiladelphiaUSA
  4. 4.Department of Psychiatry and NeurologyUniversity of PittsburghPittsburghUSA

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