NEUROENDOCRINE RESPONSE TO CLONIDINE AND 8-OH-DPAT IN RATS FOLLOWING CHRONIC ADMINISTRATION OF DESIPRAMINE OR SERTRALINE

Citation
Jm. Odonnell et M. Grealy, NEUROENDOCRINE RESPONSE TO CLONIDINE AND 8-OH-DPAT IN RATS FOLLOWING CHRONIC ADMINISTRATION OF DESIPRAMINE OR SERTRALINE, British Journal of Pharmacology, 105(4), 1992, pp. 863-868
Citations number
39
Language
INGLESE
art.tipo
Article
ISSN journal
0007-1188
Volume
105
Issue
4
Year of publication
1992
Pages
863 - 868
Database
ISI
SICI code
0007-1188(1992)105:4<863:NRTCA8>2.0.ZU;2-0
Abstract
1 Rats were administered either desipramine (DMI) or sertraline daily at doses 7.5 mg kg-1 or 10 mg kg-1, i.p., respectively and the effects on the functional state of hypothalamic neuroendocrine control mechan isms assessed by measurements of plasma hormones following acute drug challenge. The effects of treatment on gross behaviour and brain adren oceptor density were also determined. 2 Both DMI and sertraline caused significant reduction in activity measured as ambulation and rearing at 14 days of treatment. 3 All animals were chronically cannulated aft er 14 days of treatment and tested for neuroendocrine response to acut e i.v. clonidine (50-mu-g kg-1) or 8-hydroxy-2-(di-n-propylamino)tetra lin (8-OH-DPAT, 250-mu-g kg-1) after 21 or more days of treatment. 4 R ats treated with DMI but not sertraline showed a virtually complete su ppression of the growth hormone (GH) secretion elicited by clonidine i n controls, while the secretion of corticosterone was augmented. 5 Tre atment with DMI but not sertraline led to a significantly greater 8-OH -DPAT-induced secretion of prolactin than in the control rats, while t he plasma concentrations of corticosterone following 8-OH-DPAT were no t influenced by either DMI or sertraline treatment. 6 The density (but not the affinity) of cerebral cortical binding of [H-3]-dihydroalpren olol was significantly reduced by DMI treatment. 7 These results show that DMI treatment blunted the sensitivity of post-synaptic alpha(2)-a drenoceptors, accompanied by complex interactions manifested as increa sed responsiveness of alpha(1)-adrenoceptors and 5-HT1A receptors. Ser traline had no significant neurendocrine effects at a dose which signi ficantly reduced gross activity.