Continuous measurement of blood flow in the superior sagittal sinus
of the lamb.
Grant, Daniel A., Carlo Franzini, Jennene Wild, and Adrian M. Walker.
Institute of Reproduction and Development, Monash University,
Clayton, Victoria, 3168, Australia; and Institute of Human
Physiology, University of Bologna, I-40127 Bologna, Italy
APStracts 2:0074R, 1995.
We assessed the validity of recording blood flow in the superior
sagittal sinus (Qss) as a measure of cerebral blood flow (CBF). While
anesthetized, 10 lambs were instrumented with: a transit-time
ultrasonic flow probe around the superior sagittal sinus to measure
Qss; electrodes to assess sleep state; catheters to measure cerebral
perfusion pressure (Pcp); and an occlusive cuff around the common
brachiocephalic artery to vary blood pressure. After 72h recovery,
lambs were studied during spontaneous sleep-wake cycles to establish:
1) the normal range of Qss; and 2) the response rate of Qss to rapid
alterations of Pcp. Subsequently, the lambs were re-anesthetized and
the measurement of Qss was calibrated and validated. Qss was linearly
related to the arterial inflow of 35% of the brain mass (y = 0.5x +
1.6, r = 0.93, n=4). Qss was greater in active sleep (154.1 +/- 45.7
ml/min/100g, mean +/- SD, n=5) than quiet sleep (107 +/- 44.3
ml/min/100g, P<0.05). Qss responded rapidly (within one beat) to
spontaneous and to induced transient changes in Pcp. We conclude that
recording blood flow in the superior sagittal sinus provides a
simple, continuous, and quantitative measure of CBF from a defined
area of the brain and is appropriate for studying transient changes
in the cerebral circulation.
Received 8 November 1994; accepted in final form 6 March 1995.
APS Manuscript Number R641-4.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 April 1995.