Distribution of N-type Ca2 channel binding sites in rabbit brain following central administration of ω-conotoxin GVIA

Abstract

Central administration of the N-type Ca2+ channel blocker ω-conotoxin GVIA in conscious rabbits has previously been shown to result in a slowly developing hypotensive and sympatholytic effect, with peak changes observed after 48 h. The aim of the current study was to examine the distribution of [125I]ω-conotoxin GVIA binding in rabbit brain alone or following a prior i.c.v. injection of ω-conotoxin GVIA to determine the site(s) of action of centrally administered ω-conotoxin GVIA. Brains were removed from rabbits 2 or 48 h after central administration of vehicle or non-labelled ω-conotoxin GVIA (30 pmol/kg, i.c.v.). Brain sections were then incubated with [125I]ω-conotoxin GVLA (50 pM) and t..