Summary
The effects of ventricular fluid osmolality on the bulk flow of nascent fluid into the cerebral ventricles of anesthetized cats was measured during ventriculocisternal perfusion. This nascent fluid consists of both cerebrospinal fluid (CSF) and fluid which results from an osmotic gradient between ventricular fluid and the blood and/or brain. Perfusions were carried out with both mock CSF and with solutions containing either sucrose, urea, or NaCl. Differences between the normal bulk flow rate of nascent CSF and bulk flow rate measured during perfusion with anisotonic solutions were linearly related to corresponding differences in osmolality of the effluent fluid from the ventricles. The coefficients of osmotic flow using sucrose (0.231 μl/min per mOsm) and NaCl (0.224) were similar, and greater than that using urea (0.156).
During perfusion with sucrose when effluent osmolality increased by 200 mOsm (63% of normal), bulk flow rate of nascent fluid increased by 50 μl/min (200% of normal). Flow was undetectable when the effluent osmolality was 190 mOsm (decrease of 135 mOsm), although osmotically active particles continued to enter the ventricular system. Intravenous injection of acetazolamide reduced these coefficients to similar values of 0.0963 for NaCl, and 0.0955 for urea. In all experimental conditions no changes were found in cerebral water content. These results suggest that the increased bulk flow which occurs during perfusion with hypertonic solutions originates from the choroid plexus.
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References
Ames, A., III, Sakanoue, M., Endo, S.: Na, K, Ca, Mg and Cl concentrations in choroid plexus fluid and cisternal fluid compared with plasma ultrafiltrate. J. Neurophysiol. 27, 672–681 (1964)
Coulter, N.A.: Filtration coefficient of the capillaries of the brain. Amer. J. Physiol. 195, 459–464 (1958)
Curl, F.D., Pollay, M.: Transport of water and electrolytes between brain and ventricular fluid in the rabbit. Exp. Neurol. 20, 558–574 (1968)
Davson, H.: Physiology of Cerebrospinal Fluid. Boston: Little, Brown & Co. 1967
Davson, H., Pollay, M.: The turnover of 24Na in the cerebrospinal fluid and its bearing on the blood-brain barrier. J. Physiol. (Lond.) 167, 247–255 (1963)
Davson, H., Segal, M.B.: The effects of some inhibitors and accelerators of sodium transport on the turnover of 22Na in the cerebrospinal fluid and the brain. J. Physiol. (Lond.) 209, 131–153 (1970)
DiMattio, J., Hochwald, G.M., Malhan, C., Wald, A.: Effects of changes in serum osmolarity on bulk flow of fluid into cerebral ventricles and on brain water content. Pflügers Arch. 359, 253–264 (1975)
Fenstermacher, J.D., Johnson, J.A.: Filtration and reflection coefficients of the rabbit blood-brain barrier. Amer. J. Physiol. 211, 341–346 (1966)
Heisey, S.R., Held, D., Pappenheimer, J.R.: Bulk flow and diffusion in the cerebrospinal fluid system of the goat. Amer. J. Physiol. 203, 775–781 (1962)
Hochwald, G.M., Malhan, C., Brown, J.: Effect of hypercapnia on CSF turnover and blood-CSF barrier to protein. Arch. Neurol. (Chic.) 28, 150–155 (1973)
Hochwald, G.M., Wald, A., DiMattio, J., Mahan, C.: The effects of serum osmolarity on cerebrospinal fluid volume flow, Life Sci. 15, 1309–1316 (1974)
Hochwald, G.M., Wallenstein, M.: Exchange of albumin between blood, brain, and cerebrospinal fluid in the cat. Amer. J. Physiol. 212, 1199–1204 (1967)
Johanson, C.E., Folz, F.M., Thompson, A.M.: The clearance of urea and sucrose from isotonic and hypertonic fluids perfused through the ventriculocisternal system. Exp. Brain Res. 20, 18–31 (1974)
Katzman, R., Pappius, H.M.: Brain Electrolytes and Fluid Metabolism. Baltimore: The Williams & Wilkins Co. 1973
Lux, W.E., Hochwald, G.M., Sahar, A., Ransohoff, J.: Periventricular water content: effect of pressure in chronic hydrocephalus. Arch. Neurol. (Chic.) 23, 475–479 (1970)
Maren, T.H.: Bicarbonate formation in cerebrospinal fluid: role in sodium transport and pH regulation. Amer. J. Physiol. 222, 885–899 (1972)
Pappenheimer, J.R., Heisey, S.R., Jordan, E.F.: Active transport of Diodrast and phenolsulphonphthalein from cerebrospinal fluid to blood. Amer. J. Physiol. 200, 1–10 (1961)
Pollay, M., Curl, F.: Secretion of cerebrospinal fluid by the ventricular ependyma of the rabbit. Amer. J. Physiol. 213, 1031–1038 (1967)
Sahar, A., Hochwald, G.M., Sadik, A.R., Ransohoff, J.: Cerebrospinal fluid absorption in animals with experimental obstructive hydrocephalus. Arch. Neurol. (Chic.) 21, 638–644 (1969)
Voetmann, E.: On the structure and surface area of the human choroid plexuses. Acta anat. (Basel) 8, Suppl. 10 (1949)
Wald, A., Hochwald, G.M., Malhan, C.: The relationship between sodium influx and volume flow into the cerebral ventricles of cats. J. Neurochem. 25, 151–154 (1975)
Wald, A., Hochwald, G.M., Malhan, C.: Movement of sodium from blood and brain into the cerebral ventricles of cats during altered CSF volume flow rates. Exp. Neurol. 50, 304–311 (1976)
Welch, K., Sadler, K., Gold, G.: Volume flow across choroidal ependyma of the rabbit. Amer. J. Physiol. 210, 232–236 (1966)
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Wald, A., Hochwald, G.M. & Malhan, C. The effects of ventricular fluid osmolality on bulk flow of nascent fluid into the cerebral ventricles of cats. Exp Brain Res 25, 157–167 (1976). https://doi.org/10.1007/BF00234900
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DOI: https://doi.org/10.1007/BF00234900