Galas MC, Bernad N, Martinez J. Pharmacological studies on CCKB receptors in guinea pig synaptoneurosomes.
Eur J Pharmacol 1992;
226:35-41. [PMID:
1327841 DOI:
10.1016/0922-4106(92)90080-f]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Preliminary studies on CCK receptors in the central nervous system were carried out on guinea pig cerebral cortical synaptoneurosome preparations. In binding assays, the range of affinity of CCK-8, Boc-[Nle28,Nle31]CCK-7, a potent CCK analog, Boc-[Leu31]CCK-4 and of the two benzodiazepine CCK receptor antagonists L-365,260 and MK-329, is in agreement with the presence of CCKB receptors on this model. The effects of Boc-[Nle28,Nle31]CCK-7 on inositol phosphates, cAMP accumulation and 45Ca2+ efflux were investigated. Neither inositol phosphate nor cAMP accumulations could be observed. On the other hand, evidence of Boc-[Nle28,Nle31]CCK-7-, CCK-8- and Boc-[Leu31]CCK-4-induced 45Ca2+ efflux was found in a dose-dependent manner. The CCKB-selective receptor antagonist L-365,260 and, with a weaker efficiency, the CCKA-selective receptor antagonist MK-329, are able to block a maximal effect of Boc-[Nle28,Nle31]CCK-7-induced 45Ca2+ efflux, suggesting that CCKB receptors may regulate calcium ion mobilization.
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