The animals used in this study were maintained in accordance with the Guide for the Care and Use of Laboratory Animals published by the US National Institution of Health (NIH Publication No 85-23, revised 1996) and the Policy of Animal Care and Use Committee of Tongji University. Male Sprague-Dawley rats (200–220 g) and rats at the 1st, 4th, and 8th week after birth were obtained from B&K Universal Group Limited (Shanghai, China). Adult rats were fed with chow and water ad libitum at the Animal Center of Tongji Hospital, and maintained under controlled temperature (20–22°C) and a 12 h light/dark cycle.
Adult rats were randomly divided into three groups: control group (n = 21), BoNT/A group (n = 21), and agrin-Ab groups. BoNT/A (BOTOX®, Allergan, Co. Mayo, Ireland) was reconstituted in saline (NS) to a final concentration of 2 U/100 μL. Animals of the BoNT/A and agrin-Ab groups were injected unilaterally with 100 μL BoNT/A in the right gastrocnemius muscle under anesthesia with an intraperitoneal injection of pentobarbital (30 mg/kg). On the 3rd day after BoNT/A injection, the each subgroups of agrin-Ab were injected with 100 μL agrin-Ab (R&D Systems, Minnesota, CA, United States) at a dosage of 0.6, 2, 6, 20, or 60 μg respectively at once. Controls received an equivalent volume of NS injections in the right gastrocnemius muscle.
Adult rats were randomly divided into three groups: control group (n = 21), BoNT/A group (n = 21), and agrin-Ab groups. BoNT/A (BOTOX®, Allergan, Co. Mayo, Ireland) was reconstituted in saline (NS) to a final concentration of 2 U/100 μL. Animals of the BoNT/A and agrin-Ab groups were injected unilaterally with 100 μL BoNT/A in the right gastrocnemius muscle under anesthesia with an intraperitoneal injection of pentobarbital (30 mg/kg). On the 3rd day after BoNT/A injection, the each subgroups of agrin-Ab were injected with 100 μL agrin-Ab (R&D Systems, Minnesota, CA, United States) at a dosage of 0.6, 2, 6, 20, or 60 μg respectively at once. Controls received an equivalent volume of NS injections in the right gastrocnemius muscle.