Glibenclamide, one of the most potent antidiabetic sulfonylureas, inhi
bits the activity of ATP-sensitive K+ channels in the pancreas as well
as in the brain through its binding to specific receptors. Quantitati
ve autoradiography was used to localize such receptors in the brain of
rat, mouse, guinea-pig and marmoset, using H-3!glibenclamide as radi
oligand. In all four species, specific glibenclamide binding sites wer
e found to be heterogeneously distributed. The highest densities were
in the cerebral cortex, the molecular layer of the cerebellar cortex,
the thalamus and the caudate-putamen. The globus pallidus and the subs
tantia nigra were highly labelled in rat and mouse but poorly labelled
in guinea-pig and marmoset. The distribution of glibenclamide binding
sites in the hippocampus was different between the rodents and marmos
et; in rodents, most binding sites were distributed in the fascia dent
ata and the CA3-CA4 fields of Ammon's horn, contrasting with a very ho
mogeneous distribution in all subfields of the marmoset hippocampus. I
n conclusion, we demonstrate that primate brain contains specific bind
ing sites for H-3!glibenclamide with a distribution not exactly simil
ar to that in rodent brain.