tokens: The antinociceptive effect of 3 alpha - tropyl 2 - ( p - bromophenyl ) propionate [ ( + / - ) - PG - 9 ] ( 10 - 40 mg kg - 1 s . c . ; 30 - 60 mg kg - 1 p . o . ; 10 - 30 mg kg - 1 i . v . ; 10 - 30 micrograms / mouse i . c . v . ) was examined in mice , rats and guinea pigs by use of the hot - plate , abdominal - constriction , tail - flick and paw - pressure tests .