Fig. 3.

THC-induced apoptosis in the fetal thymus is mediated through both CB1 and CB2. On GD16, groups of two C57BL/6 pregnant mice (n = 2) were pretreated with CB1 (SR141716A) (A and B) or CB2 (AM630) (C and D) antagonist followed by injection with 50 mg/kg THC or the vehicle. A and C, on GD17, the thymi from the fetuses of each mother (average 10) were pooled and analyzed for viable cells as described in Fig. 2. The data represent the mean thymic cellularity per fetus ± S.E.M. A, ***, p < 0.0001, one-way ANOVA. C, p = 0.0062 one-way ANOVA. Asterisks indicate statistically significant difference (**, p < 0.05) in the mean cellularity in THC + antagonist group compared with THC-treated group and in the THC-treated group compared with vehicle-treated group. B and D, the thymocytes were analyzed for apoptosis using the TUNEL followed by flow cytometric analysis. The percentage of apoptotic cells is depicted in each histogram.