title: The effect of glucocorticoids on the anxiolytic efficacy of buspirone.
abstract: BACKGROUND
  The serotonergic system and the hypothalamus-hypophysis-adrenocortical axis reciprocally influence each other. Therefore, the interaction between stress and serotonergic anxiolytics should be of major concern for both laboratory investigations and clinical treatment.
  
  
  OBJECTIVE
  We have studied the effects of the serotonergic anxiolytic buspirone in rats in which basal levels of glucocorticoids were low and stable, while acute stress reactions were inhibited or exogenously induced.
  
  
  METHODS
  Rats were adrenalectomised. Subcutaneous corticosterone pellets maintained basal glucocorticoid concentrations while acute changes were mimicked by corticosterone injections. Anxiety was assessed by the social interaction test. Temporal changes were evaluated by submitting rats to the same manipulations three times at two-day intervals.
  
  
  RESULTS
  Buspirone applied to animals with stable and low plasma glucocorticoid concentrations induced a dramatic increase in social interactions. A slight locomotor suppressive effect was also noticed. The effects of buspirone proved to be stable over time in these animals. Acute treatment with corticosterone doubled the locomotor suppressive effects of buspirone and reversed its anxiolytic effects: the buspirone-corticosterone combination was anxiogenic after the first application. During the second and third treatment, the impact of corticosterone on buspirone efficacy gradually decreased, but the combined treatment remained about half as effective in reducing anxiety as buspirone alone.
authors.affiliation: Institute of Experimental Medicine, Hungarian Academy of Science, P.O. Box 67, 1450 Budapest, Hungary. haller@koki.hu
authors.forename: J
authors.initials: J
authors.lastname: Haller
authors.forename: C
authors.initials: C
authors.lastname: Leveleki
authors.forename: J
authors.initials: J
authors.lastname: Halász
authors.forename: J
authors.initials: J
authors.lastname: Baranyi
authors.forename: G B
authors.initials: GB
authors.lastname: Makara
mesh_terms: D000315:Adrenalectomy; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001007:Anxiety / Q000523:psychology; D001522:Behavior, Animal / Q000187:drug effects*; D002065:Buspirone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005938:Glucocorticoids / Q000494:pharmacology*; D007398:Interpersonal Relations; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000523:psychology
chemical_list: D014151:Anti-Anxiety Agents; D005938:Glucocorticoids; D002065:Buspirone