Diffusion analysis of valproate and trans-2-en-valproate in agar and in cerebral cortex of the rat.
The diffusion of valproate (VPA) and trans-2-en-valproate were studied in agar gel and in the cerebral cortex of the rat using pressure microejection and VPA-selective microelectrodes. From the agar measurements a free diffusion coefficient for VPA of 6.52 x 10(-6) cm2.s-1 and for trans-2-en-VPA of 5.25 x 10(-6) cm2.s-1 for 37 degrees C was determined. The tortuosity value in the cortex was 1.92 for VPA and 1.67 for trans-2-en-VPA. The tortuosity values suggest that VPA and trans-2-en-VPA diffuse mainly in the extracellular space of the brain.
Lücke
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Institut für Physiologie der Universität Münster, FRG.
Lehmenkühler
A
A
Altrup
U
U
Nicholson
C
C
Reith
H
H
Schmitz-Moormann
C
C
Speckmann
E J
EJ
D000362:Agar / Q000032:analysis*; D000818:Animals; D002540:Cerebral Cortex / Q000737:chemistry* / Q000187:drug effects; D004058:Diffusion; D005110:Extracellular Space / Q000737:chemistry; D005229:Fatty Acids, Monounsaturated / Q000032:analysis*; D008297:Male; D008839:Microelectrodes; D008845:Microinjections; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014635:Valproic Acid / Q000008:administration & dosage / Q000032:analysis*
D005229:Fatty Acids, Monounsaturated; D000644:Quaternary Ammonium Compounds; C014168:2-propyl-2-pentenoic acid; D014635:Valproic Acid; D000362:Agar; C027917:tetramethylammonium