The 5-HT1A receptor is not involved in emotional stress-induced rises in stress hormones.
To determine whether emotional stress-induced rises in stress hormone levels are mediated by activation of 5-HT1A receptors, we studied the effects of the selective 5-HT1A receptor antagonist, N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexanecarboxamide trihydrochloride (WAY-100635) on plasma ACTH, corticosterone, prolactin, and glucose levels in the conditioned ultrasonic vocalisation (USV) model in adult rats. The effects of WAY-100635 on USVs were also investigated in this paradigm. WAY-100635 (0.3, 1, and 3 mg/kg SC) had no clear effects on basal plasma ACTH, corticosterone, and glucose levels, but the 3 mg/kg dose significantly increased the plasma prolactin levels. The increases in plasma ACTH, corticosterone, and prolactin levels induced by the USV procedure were not affected by WAY-100635. This indicates that the 5-HT1A receptor does not play a major role in the distress-induced activation of the hypothalamic-pituitary-adrenal axis and prolactin secretion. The USVs were significantly enhanced by low doses of WAY-100635 (0.03 and 0.3 mg/kg SC), whereas higher doses (1.0 and 3.0 mg/kg SC) had no effect. These findings suggest that blockade of 5-HT1A receptors during stress may enhance the behavioural stress-response.
Groenink
L
L
Department Psychopharmacology, Faculty of Pharmacy, Utrecht, The Netherlands.
Mos
J
J
Van der Gugten
J
J
Olivier
B
B
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004597:Electroshock; D004644:Emotions / Q000502:physiology*; D006728:Hormones / Q000097:blood*; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D011388:Prolactin / Q000097:blood; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D013315:Stress, Psychological / Q000378:metabolism*; D014828:Vocalization, Animal / Q000187:drug effects
D001786:Blood Glucose; D006728:Hormones; D010879:Piperazines; D011725:Pyridines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D000324:Adrenocorticotropic Hormone; D011388:Prolactin