'Anxiolytic' effect of CCK-antagonists on plus-maze behavior in mice.

The effects of systemic treatment with the CCK-B receptor antagonist L-365,260, its 3S-(-) enantiomer and the CCK-A receptor antagonist devazepide were assessed in the plus-maze procedure in mice. L-365,260 (1-1000 micrograms.kg-1 i.p.) produced a dose-dependent increase in the percentage of entries into, and the percentage of time spent in the open arms. Total arm entry was not consistently modified. Neither the 3S-(-) enantiomer of L-365,260 nor devazepide (both administered at 100-10,000 micrograms.kg-1) enhanced the exploratory behavior of mice. These results suggest that CCK-B, rather than CCK-A antagonists may possess 'anxiolytic' properties in mice.