(Stroke. 2000;31:1194.)
© 2000 American Heart Association, Inc.
Letters to the Editor |
Failure of Standards in Reporting the Composition of Artificial Cerebral Spinal Fluid in Studies of the Pial Blood Vessels
Department of Pathology, Medical College of Virginia, at Virginia Commonwealth University, Richmond, Virginia
Key Words: cerebral vessels • cerebrospinal fluid • animal
models
To the Editor:
Reproducible experimental results require the replication of the
experimental conditions under which the experiment was first performed.
Relevance to humans may depend on the degree to which those conditions
resembled those to which humans are exposed. With respect to studies of
vascular reactivity, a most important parameter is the
composition of the fluid bathing the vessel. For vessels on the brains
surface, so-called pial vessels, this fluid is the cerebrospinal fluid
(CSF). Experiments studying these vessel, in vivo or in vitro,
generally bathe the vessels in an artificial CSF, sometimes called a
"mock" CSF, or some other fluid, sometimes called a
physiological salt solution and sometimes simply a
buffered solution. A question that should immediately arise, if
relevance to humans is an issue, is whether the fluid used has the
composition of cerebrospinal fluid, and if so, is it the composition of
the experimental species’ CSF or of human CSF. At present there is
no data to tell us whether or not it would be better to always
replicate the composition of human CSF, even if this differs from that
of the animal in use, or whether, instead, the mock CSF should resemble
that of the animal itself. CSF contains urea, but not everyone adds
urea to the artificial CSF, and there are no studies showing the effect
of the urea on the vascular responses. Indeed there is virtually no
information on the effect of altering one or more aspects of CSF
composition, other than pH and