Premium
Sodium exchange between blood, brain, and CSF in normal and hydrocephalic cats
Author(s) -
Hochwald G. M.,
Wald A.,
Marlin A. E.,
Stern J.,
Malhan C.
Publication year - 1977
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490030404
Subject(s) - cats , cerebrospinal fluid , white matter , choroid plexus , chemistry , perfusion , sodium , anatomy , endocrinology , pathology , medicine , central nervous system , organic chemistry , magnetic resonance imaging , radiology
The exchange of sodium between blood, brain, and cerebrospinal fluid was studied in normal and kaolin‐induced hydrocephalic cats. The ventricles were perfused to measure fluid formation and Na + exchange rates. 22 Na was added to the perfusion fluid or injected intravenously as a tracer for Na + movement. Na + and 22 Na were also measured in cortical gray and white matter. Na + relative specific activities were calculated for brain, effluent fluid, and serum. With 22 Na in the perfusion fluid, Na + exchange was not different from nascent Na + influx for both normal and hydrocephalic cats. Na + relative specific activities of cortical gray and white matter were 10 times greater in hydrocephalic than in normal cats. This difference in Na + relative specific activity for brain may be due to a higher diffusion constant or to a lower brain capillary permeability. When 22 Na was given intravenously, the Na + diffusional exchange for normal cats was less than that measured when 22 Na + was in the perfusion fluid. In hydrocephalic cats, the Na + diffusional exchange was effectively zero. Na + relative specific activities of cortical gray and white matter were the same for normal and hydrocephalic cats. These findings suggest that the impaired Na + diffusional exchange may be due to pathological changes in the choroid plexus.