Premium
Benzodiazepine/cholecystokinin interactions at functional CCK receptors in rat brain
Author(s) -
Boden P.R.,
Woodruff G.N.
Publication year - 1994
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1994.tb13090.x
Subject(s) - flurazepam , cholecystokinin , chemistry , cholecystokinin receptor , medicine , agonist , receptor , endocrinology , dorsal raphe nucleus , pharmacology , benzodiazepine , biology , biochemistry , serotonin , serotonergic
1 The effects of benzodiazepines on cholecystokinin (CCK) responses produced following activation of CCK B receptors by pentagastrin in the ventromedial hypothalamus (VMH) or CCK A receptors by CCK‐8S in the dorsal raphe of the rat brain in vitro have been investigated. 2 The benzodiazepine agonist, flurazepam, at high concentrations, blocked pentagastrin‐induced excitations in the rat VMH yielding an equilibrium constant ( K e ) value of 12.5 μ m . 3 In the rat dorsal raphe, where activation of CCK A receptors leads to neuronal depolarization, flurazepam also produced a weak block of the CCK response. 4 Flurazepam blocked CCK responses but not carbachol‐induced excitations of VMH neurones. The inhibition of CCK responses by flurazepam was not blocked by the benzodiazepine antagonist, flumazenil. 5 These data suggest that flurazepam is a weak antagonist at central CCK B receptors. 6 At central CCK A receptors, flurazepam blocked CCK‐8S responses but the inhibition was not competitive, with a reduction in the peak CCK‐8S obtainable in the presence of flurazepam. These results suggest that flurazepam acts at a site other than the CCK A receptor itself to block CCK responses in the dorsal raphe.