RATIONALE: FK506 inhibits calcineurin activity, resulting in the inhibition of calcium-dependent intracellular processes. Recent studies have suggested that intracellular calcium is likely to be involved in methamphetamine (MAP)-induced locomotor activity and stereotyped behavior, and in the development of sensitization to MAP. OBJECTIVES: We investigated the effects of FK506 on MAP-induced behavioral changes and the development of sensitization in rats. METHODS: In experiment 1, animals were administered IP 2 mg/kg FK506 or vehicle followed 10 min later by MAP (1, 2, 4 and 8 mg/kg, IP). Another set of animals were administered FK506 (0.1, 2, 5 and 10 mg/kg) followed by 2 mg/kg MAP. Locomotor activity and stereotyped behavior were assessed. In experiment 2, animals received repeated IP injections of 2 mg/kg MAP pretreated with 2 mg/kg FK506 or vehicle for 5 consecutive days. One week later, rats were challenged with 1 mg/kg MAP. RESULTS: Pretreatment with 2 mg/kg FK506 caused a rightward shift of the inverted U-shaped response curve of the locomotor activity induced by 1-8 mg/kg MAP. The same pretreatment significantly attenuated augmentation of the MAP-induced stereotyped behavior. FK506 at doses of 0.1-10 mg/kg dose-dependently inhibited the behavioral response induced by 2 mg/kg MAP. Coadministration of 2 mg/kg FK506 with 2 mg/kg MAP for 5 consecutive days resulted in significant suppression of the behavioral response to challenge with 1 mg/kg MAP. CONCLUSIONS: These results suggest that calcineurin plays an important role in MAP-induced behavioral changes and sensitization, especially the latter.
RATIONALE: FK506 inhibits calcineurin activity, resulting in the inhibition of calcium-dependent intracellular processes. Recent studies have suggested that intracellular calcium is likely to be involved in methamphetamine (MAP)-induced locomotor activity and stereotyped behavior, and in the development of sensitization to MAP. OBJECTIVES: We investigated the effects of FK506 on MAP-induced behavioral changes and the development of sensitization in rats. METHODS: In experiment 1, animals were administered IP 2 mg/kg FK506 or vehicle followed 10 min later by MAP (1, 2, 4 and 8 mg/kg, IP). Another set of animals were administered FK506 (0.1, 2, 5 and 10 mg/kg) followed by 2 mg/kg MAP. Locomotor activity and stereotyped behavior were assessed. In experiment 2, animals received repeated IP injections of 2 mg/kg MAP pretreated with 2 mg/kg FK506 or vehicle for 5 consecutive days. One week later, rats were challenged with 1 mg/kg MAP. RESULTS: Pretreatment with 2 mg/kg FK506 caused a rightward shift of the inverted U-shaped response curve of the locomotor activity induced by 1-8 mg/kg MAP. The same pretreatment significantly attenuated augmentation of the MAP-induced stereotyped behavior. FK506 at doses of 0.1-10 mg/kg dose-dependently inhibited the behavioral response induced by 2 mg/kg MAP. Coadministration of 2 mg/kg FK506 with 2 mg/kg MAP for 5 consecutive days resulted in significant suppression of the behavioral response to challenge with 1 mg/kg MAP. CONCLUSIONS: These results suggest that calcineurin plays an important role in MAP-induced behavioral changes and sensitization, especially the latter.
Authors: Elaine D Por; Bret K Samelson; Sergei Belugin; Armen N Akopian; John D Scott; Nathaniel A Jeske Journal: Biochem J Date: 2010-12-15 Impact factor: 3.857
Authors: Jun Wang; Li-Li Sun; Wei-Li Zhu; Yan Sun; Jian-Feng Liu; Lin Lu; Jie Shi Journal: Psychopharmacology (Berl) Date: 2011-09-08 Impact factor: 4.530