The effects of centrally acting adrenergic agonists on temperature and on explorative and motor behaviour. Relation with effects on quasi-morphine withdrawal behaviour.
Seven structurally unrelated adrenergic agonists were compared in three models to measure sedation viz. hole-board exploration, open-field activity and rotarod performance. It appeared that all compounds exerted the same order of potency in these models except for BHT-920 which was more active in the open-field. The other compounds were clonidine, azepexole, guanfacine, lofexidine, UK-14.304 and ST-587. The sedative effect appeared to be not causally related with the hypothermic activity since much higher doses were necessary for the latter effect. There was a relation between the sedative effects and the suppression of body shakes and enhanced locomotor activity induced by dipropylacetate, a potent model for morphine-withdrawal behaviour. The body shakes appeared to be more sensitive than locomotor activity suggesting that the antiwithdrawal action of alpha 2-agonists might be intrinsically higher than their sedative action. The data support earlier findings indicating that the antiwithdrawal action of clonidine is mediated by alpha 2-adrenoceptors.
Van der Laan
J W
JW
Van Veenendaal
W
W
Voorthuis
P
P
Weick
G
G
Hillen
F C
FC
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D005106:Exploratory Behavior / Q000187:drug effects*; D006801:Humans; D008297:Male; D009020:Morphine / Q000009:adverse effects; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013375:Substance Withdrawal Syndrome / Q000517:prevention & control*; D014635:Valproic Acid / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D014635:Valproic Acid; D009020:Morphine