(VPU), (Fig.!) is a valproic acid
analogue which has been reported in
various animal models, to possess a higher
anticonvulsant activity in parallel with a
greater relative margin of safety while
offering less unwanted effect than its parent
compound, valproic acid or VPA1
• No effect
of VPU and VP A has been observed on
total cytochrome P450 or CYP!Al 1A2
or 2El activities of rats. However,' VPU
has been found to significantly increase
CYP 2B 1 and 2B2 activities'. Preliminary
studies of pharmacokinetic as well as
embryotoxic of this compound have been
reported3
'
4
• Many of the conventional
antiepileptic drugs as well as those which
just have been released into the market or
newly discovered have been noted for
their depressant effect on either the
spontaneously or stimulus-driven firing
neurons of the experimental animal's
brain and thus may account for the
anticonvulsant effect observed"'· In the
present study, we used microiontophoretic
technique in combination with micropres·sure
application to investigate the effect of VPU,
in comparison with VP A, on neurons of
the cerebral cortex and Purkinje cells of
cerebellum of rats anesthetized with urethane.
Interactions between VPU and other well
established amino acid neurotransmitters
or compounds with well defined mechanism
of action were also observed.