ISSN:
1432-1106
Keywords:
Anisotonic perfusion fluid
;
Osmotic effects
;
Ependyma
;
Cerebrospinal fluid transport
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The ventriculo-cisternal perfusion technique was utilized in anaesthetized goats to investigate the clearance of urea and sucrose from isotonic and hypertonic perfusion fluids. Diffusional outflux coefficients of 0.114±0.015 (SEM) and 0.030±0.003 ml/min were found for urea and sucrose, respectively, in the isotonic (control) perfusions; these coefficients increased by 40% and 83%, respectively, in the hypertonic (0.40 osmolal) perfusions. Changes in ventricular hydrostatic pressure were not of sufficient magnitude, and changes in fluid accretion (osmotic flow from brain to ventricular fluid) were not in the right direction, to explain the enhanced clearance of nonelectrolytes in the experimental perfusions. The outflux coefficient data, together with previously reported osmometric data, support the hypothesis that the increased clearance of urea and sucrose from the hypertonic perfusion fluids is primarily the result of expansion of intercellular channels (due to cell shrinkage) between ependymal and parenchymal cells. Some of the factors affecting indicator clearance from isotonic perfusion fluid (e.g. perfusion rate, unilateral vs. bilateral ventriculo-cisternal perfusion, anesthetic, and anatomical barriers) have been further evaluated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00239015
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