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Impairment of stress adaptive behaviours in rats by the CCK A receptor antagonist, devazepide
Author(s) -
Hernando Fernando,
Fuentes José A.,
RuizGayo Mariano
Publication year - 1996
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.1476-5381.1996.tb15416.x
Subject(s) - cholecystokinin , endocrinology , medicine , agonist , antagonist , cholecystokinin receptor , corticosterone , receptor antagonist , period (music) , behavioural despair test , receptor , hormone , hippocampus , physics , acoustics , antidepressant
1 Cholecystokinin (CCK) is released during stress both in limbic and hypothalamic areas suggesting that CCK could participate in modulating neuroendocrine as well as behavioural responses to stress. 2 In this study we have examined the effect of CCK receptor antagonists on the retention of the immobility response to a forced‐swim stress in rats. In this test, rats are forced to swim during 15 min (conditioning period) and 24 h later, the duration of immobility is measured during a period of 5 min (re‐test period). During the conditioning period rats display a period of vigorous activity, followed by progressive inactivity. During the re‐test period rats remain 70–80% of the time in an immobile posture. 3 The CCK A receptor antagonist, devazepide (MK‐329) but not the CCK B receptor antagonist, L‐365,260, administered s.c. immediately before the conditioning period, decreased the duration of acquired immobility during the re‐test period. The effect of devazepide was prevented by cholecystokinin octapeptide (CCK‐8; 40 μg kg −1 , s.c.) as well as by the selective glucocorticosteroid G II receptor agonist, dexamethasone (30 μg kg −1 , s.c.). 4 Neither corticosterone nor ACTH plasma levels measured both after the re‐test period and after the conditioning period were modified by devazepide treatment. 5 The results suggest a role for CCK in the behavioural adaptation to stress and indicate a relationship between CCK systems and glucocorticoids in the neuronal mechanisms involved in the acquisition of adaptive behaviours to stress.