Rats: Intracerebroventricular administration of BIBO-3304 (1, 10, 50 nmol) had no effect on locomotor activity as measured by number of rearings and number of squares visited in an open field test in rats, but at 50 nmol dose defecation was significantly increased. BIBO-3304 (10 nmol) reduced amphetamine-induced increases in horizontal and vertical activity whereas its S-configurated enantiomer BIBO-3457 was inactive. In an open field test BIBO-3304 (10 nmol) inhibited purposeless running in rats sensitized to direct dopaminergic agonist apomorphine (0.5 mg/kg, s.c.). BIBO-3304 (10 nmol but not 1 nmol, i.c.v.) reduced fighting in apomorphine-induced aggression paradigm.

BIBO-3304 was evaluated in terms of its properties to inhibit the NPY mediated signal transduction in SK-N-MC cells. No agonistic properties were found with 1 uM BIBO-3304 in the cAMP assay. The NPY induced inhibition of cAMP synthesis was antagonized by 100 nM BIBO-3304 with a pKb of 9.1+0.4.