Ca. Castro et al., BEHAVIORAL-EFFECTS OF VEHICLES - DMSO, ETHANOL, TWEEN-20, TWEEN-80, AND EMULPHOR-620, Pharmacology, biochemistry and behavior, 50(4), 1995, pp. 521-526
Experimental drugs and compounds that do not easily dissolve in water
or saline are frequently combined with vehicles like solvents, deterge
nts, or vegetable oils. Yet very little has been reported on the behav
ioral effects of vehicles. In this study, we assessed the effects of a
vegetable oil (emulphor-620), two detergents (Tween-20 and Tween-80),
and two solvents [dimethyl sulphoxide (DMSO) and ethanol] on the loco
motor activity in CD2F1 male mice. Locomotor activity was monitored fo
r 12 h after vehicle administration (IF). The concentrations for each
vehicle were expressed as percent of vehicle in saline (v/v). Emulphor
-620 did not affect locomotor activity at any concentration tested (2%
, 4%, 8%, 16%, and 32%). Tween-20 significantly decreased locomotor ac
tivity at a concentration of 16% and Tween-80 at 32%. DMSO significant
ly decreased locomotor activity at concentrations of 32% and 64%. In c
ontrast, ethanol produced a biphasic behavioral response: increased ac
tivity at a concentration of 16% and decreased activity at a concentra
tion of 32%. These results will facilitate the selection and concentra
tion of vehicles to be used in combination with experimental drugs or
test agents.