engleski

Influence of cerebrospinal fluid movement on Behavior of different substances in cerebrospinal and interstitial fluid

Introduction Cerebrospinal fluid (CSF) movement is not a unidirectional circulation, but the permanent rhythmic systolic-diastolic pulsation of CSF volume. That kind of CSF movement represents the main force of substances distribution along the CSF system, and from CSF via peri- and paravascular routes into the central nervous system (CNS) parenchyma interstitial space. Methods Distribution of various substances (radioactive water, organic acids, inulin etc.) has been investigated in CSF and interstitial space after their application into different CSF compartments in freely moving large animals (dogs and cats). Results Our results suggest that the distribution of substances along the CSF system is observed in all directions (in the direction of imagined circulation from brain ventricles to subarachnoid space as well as in the opposite direction), and depends on the resident time of the substance, whereby longer resident time means longer path of distribution. Quick disappearance of organic anions from central CSF compartments, and very low concentrations of the tested substances in “peripheral” CSF compartments were observed in control condition. When active transport was blocked in animals by probenecid, the concentrations of monitored substances in CNS tissue and in „peripheral“ CSF compartments were significantly increased in comparison to the control group. Conclusions Obtained results suggest that transport at the capillary endothelium has the most important role in CNS homeostasis and in removal of potentially toxic metabolites from the CNS tissue into blood circulation, and not, as was previously conceived, the unidirectional CSF circulation and its absorption through the dural sinuses.

Cerebrospinal fluid patho/physiology ; cerebrospinal fluid pressure ; distribution of substances in cerebrospinal fluid ; interstitial fluid ; new hydrocephalus definition.

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