Effects of some alpha 2-adrenergic agonists and their antagonists on food intake in dwarf goats

ABSTRACT

The effects of some alpha[2] adrenoceptor agonists and their antagonist atipamezole on food intake were studied in dwarf goats. Detomidine at the dose rate of 0.2 micro g/kg/min over 10 min failed to modify food intake during either the first or second observation period [0-30 min and 180-210 min after drug infusion respectively]. Given at a higher dosage [rate of 0.4 micro g/ min over 10 min] the drug inhibited food consumption during the first observation period but stimulate food intake during the second observation period. A similar pattern was observed often i.v. infusion with medetomidine [0.2 micro g /kg min over 10 min] romifidine [0.4 micro g /kg min over 10 min] or xylazine [1 micro g/kg/ min over 10 min]. The alpha[2] antagonist atipamezole [2 micro g/kg/min over 10 min] failed to modify food intake during either the first or second abservation period. After premedication with atipamezole the effects of alpha[2] agonists of feeding behaviour were completely antagonized. These results suggest that the CNS control of feeding differs in ruminants and monogastric species