Isatin (2,3-dioxindole) is an endogenous compound which is distributed
throughout the central nervous system. The studies reported here demo
nstrate that isatin decreased food intake in food deprived TAC (SW) ma
le mice 12-16 weeks of age. Isatin was more effective at decreasing fo
od intake when the mice had to work harder to obtain food. Isatin also
decreased sucrose, mill; and water intake. When hunger was reduced by
prefeeding milk to the mice, isatin was more effective at decreasing
food intake. Isatin did not alter spontaneous activity in an openfield
. Behaviors observed in the home cage indicated that mice which receiv
ed isatin approached the food more often without eating than the contr
ols. Movement in the home cage was significantly reduced in mice recei
ving isatin. Drinking, grooming;Ind resting were not significantly aff
ected by administration of isatin. These studies suggest that isatin m
ay be an endogenous modulator of food intake.