Dynamics of distribution of 3H-inulin between the cerebrospinal fluid compartments.
Since the distribution of substances between various cerebrospinal fluid (CSF) compartments is poorly understood, we studied (3)H-inulin distribution, over time, after its injection into cisterna magna (CM) or lateral ventricle (LV) or cisterna corporis callosi (CCC) in dogs. After the injection into CM (3)H-inulin was well distributed to cisterna basalis (CB), lumbar (LSS) and cortical (CSS) subarachnoid spaces and less distributed to LV. When injected in LV (3)H-inulin was well distributed to all CSF compartments. However, after injection into CCC (3)H-inulin was mostly localized in CCC and adjacent CSS, while its concentrations were much lower in CM and CB and very low in LSS and LV. Concentrations of (3)H-inulin in venous plasma of superior sagittal sinus and arterial plasma were very low and did not differ significantly, while its concentration in urine was very high. In (3)H-inulin distribution it seems that two simultaneous processes are relevant: a) the pulsation of CSF with to-and-fro displacement of CSF and its mixing, carrying (3)H-inulin in all directions, and b) the passage of (3)H-inulin from CSF into nervous parenchyma and its rapid distribution to a huge surface area of capillaries by vessels pulsations. (3)H-inulin then slowly diffuses across capillary walls into the bloodstream to be eliminated in the urine.
Vladić
Anton
A
Department of Pharmacology and Croatian Institute for Brain Research, University of Zagreb School of Medicine, Salata 11, 10 000 Zagreb, Croatia.
Klarica
Marijan
M
Bulat
Marin
M
D000042:Absorption; D000818:Animals; D002404:Catheterization; D002946:Cisterna Magna / Q000737:chemistry; D004058:Diffusion; D004285:Dogs; D007444:Inulin / Q000097:blood / Q000134:cerebrospinal fluid* / Q000493:pharmacokinetics / Q000652:urine; D020547:Lateral Ventricles / Q000737:chemistry; D013346:Subarachnoid Space / Q000737:chemistry
D007444:Inulin