Effects of isatin on PACAP-38-induced hyperthermia. Groups of rats received an i.p. injection of saline (PACAP 1 μg group) or different doses (12.5, 18.75, 25 or 50 mg/kg) of isatin (Isa. + PACAP groups) 3.5 h after an i.c.v. injection of 1 μg PACAP-38. The control group received an i.p. saline injection 3.5 h after i.c.v. saline treatment (groups of animals receiving different dilutions (12.5, 18.75, 25 or 50 mg/kg; i.p.) of isatin 3.5 h after an i.c.v. saline injection are not shown). Number of animals per group is presented in parentheses after the corresponding group. The vertical lines on the top of the marks denote the S.E.M. The vertical arrow denotes the time of isatin injection (3.5 h). * p < 0.05 PACAP vs. other groups; × p < 0.05 control vs. other groups; ** p < 0.05 Isa. 18.75 + PACAP compared with the control, the Isa. 25 + PACAP, the Isa. 50 + PACAP and with the PACAP 1 μg groups.