AJP - Heart and Circulatory Physiology, Vol 236, Issue 6 802-H807, Copyright © 1979 by American Physiological Society
Increased free fatty acid turnover in CSF during hypotension in dogs
E. Fritschka, J. L. Ferguson and J. J. Spitzer
Cerebrospinal fluid turnover rates of FFA were investigated using
ventriculocisternal perfusion techniques. Seven conscious dogs were
perfused over a 6-h period from the lateral ventricle to the cisterna magna
with mock cerebrospinal fluid (CSF) containing [14C]palmitate and 100
mumol/l of FFA. One hundred and twenty minutes of perfusion were allowed to
establish equilibrium of the FFA concentration in the ventricular space.
Moderate hemorrhage hypotension was then induced (MABP greater than 60
mmHg) for 3 h, followed by rapid retransfusion and a final hour of
perfusion. Cerebral blood flow did not change significantly (45 +/- 6
before, 53 +/- 6 after hemorrhage, and 47 +/- 5 ml.min-1. 100 g-1 after
retransfusion). Cerebral arteriovenous difference of O2, glucose, and pH
increased significantly during hemorrhage. Hypotension was accompanied by
an increased turnover of FFA from 60 to 120 nmol/min (P less than 0.01) in
the CSF. FFA turnover was directly correlated with the fatty acid
concentration of the CSF (r = 0.77). It is speculated that the increased
fatty acid turnover during hypotension may indicate increased phospholipid
turnover and/or increased oxidation by tissues lining the ventricular
space.
