The major thrust of this proposal is to determine the extent of capillary recruitment in the control of cerebral blood flow (CBF). The emphasis will be on the function of the control system as it is effected in the microvessels of the cerebral cortex. Both the temporal and spatial qualities of the capillary recruitment control system will be studied by altering physiological variables that affect CBF. The connection between oxygen cycles, CBF microheterogeneity or the columnar distribution of CBF, and the vascular architecture of the cortex all support the concept of a CBF control system based upon the capillary recruitment model. The purpose of this proposal is to study and define this hypothesized control system with newly developed experimental techniques. The quick snapshot of CBF that is available with the current autoradiographic techniques and the introduction of a vascular stain which can be used at the same time as a CBF study will elucidate the functioning and mechanisms of this hypothesized control system. CBF will be measured over two different intervals in the same animal using double radionuclide autoradiography. Cerebral blood volume will be determined in conjunction with CBF using the double label autoradiographic techniques. The physiological variables known to influence CBF (PaCO2, PaO2 and mean arterial blood pressure) will be altered to define the limits of the columnar structure of CBF and the relationship of this structure to capillary recruitment. The dysfunction of this hypothesized control system will be studied in ischemia, hypoxia and recovery from complete ischemia. This investigation is centered on the mechanistic and functional aspects of CBF control. The implication and applications to pathology will also be addressed.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS021538-02
Application #
3402733
Study Section
Neurology A Study Section (NEUA)
Project Start
1986-09-01
Project End
1989-08-31
Budget Start
1987-09-01
Budget End
1988-08-31
Support Year
2
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Cleveland Clinic Lerner
Department
Type
DUNS #
017730458
City
Cleveland
State
OH
Country
United States
Zip Code
44195
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Wei, D; Saidel, G M; Jones, S C (1994) Thermal method for continuous measurement of cerebral perfusion. Med Biol Eng Comput 32:481-8
Williams, J L; Shea, M; Jones, S C (1993) Evidence that heterogeneity of cerebral blood flow does not involve vascular recruitment. Am J Physiol 264:H1740-3
Wei, D; Shea, M; Saidel, G M et al. (1993) Validation of continuous thermal measurement of cerebral blood flow by arterial pressure change. J Cereb Blood Flow Metab 13:693-701
Jones, S C; Korfali, E; Marshall, S A (1991) Cerebral blood flow with the indicator fractionation of [14C]iodoantipyrine: effect of PaCO2 on cerebral venous appearance time. J Cereb Blood Flow Metab 11:236-41
Williams, J L; Jones, S C; Page, R B et al. (1991) Vascular responses of choroid plexus during hypercapnia in rats. Am J Physiol 260:R1066-70
Williams, J L; Shea, M; Furlan, A J et al. (1991) Importance of freezing time when iodoantipyrine is used for measurement of cerebral blood flow. Am J Physiol 261:H252-6
Wei, D T; Saidel, G M; Jones, S C (1990) Optimal design of a thermistor probe for surface measurement of cerebral blood flow. IEEE Trans Biomed Eng 37:1159-72
Jones, S C; Bose, B; Furlan, A J et al. (1989) CO2 reactivity and heterogeneity of cerebral blood flow in ischemic, border zone, and normal cortex. Am J Physiol 257:H473-82
Jones, S C; Lu, D F (1988) The evaluation of quantitative autoradiogram processing systems for cerebrovascular research. J Neurosci Methods 24:11-25