Simple behavioral measures of central alpha-adrenoceptor blocking activity of drugs.
Behavior of mice exposed to open field was investigated after treatment with various alpha-adrenoceptor antagonists. In addition, the interaction with clonidine and exploratory response in rats were tested. Preferential alpha-2 antagonists were found to change characteristically the open-field behavior in mice: they consistently increased grooming and decreased rearing activity. Yohimbine, rauwolscine and piperoxane produced bell-shaped effects on grooming which were compatible with their alpha-1 antagonistic activity at higher doses. Similarly, these drugs antagonized the clonidine-induced hypoactivity at lower dose-ranges and decreased the exploration in rats after higher doses. Selective alpha-1 antagonists showed only depressant effects on various behavioral measures. The results of this study indicate that the selectivity of alpha-1 or alpha-2 receptor blockade in mice and rats can be reliably determined by using behavioral parameters.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002490:Central Nervous System / Q000187:drug effects*; D003000:Clonidine / Q000037:antagonists & inhibitors; D005106:Exploratory Behavior / Q000187:drug effects; D006120:Grooming / Q000187:drug effects; D008297:Male; D051379:Mice; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects
D000317:Adrenergic alpha-Antagonists; D011942:Receptors, Adrenergic, alpha; D003000:Clonidine