The effects of manganese on neuromuscular junction transmission were studied in the isolated rat phrenic nerve diaphragm preparation, chick biventer cervicis nerve-muscle preparation and toad rectus abdominis muscle p...The effects of manganese on neuromuscular junction transmission were studied in the isolated rat phrenic nerve diaphragm preparation, chick biventer cervicis nerve-muscle preparation and toad rectus abdominis muscle preparation. It wa found that manganese could adversely andconcentration-dependently inhibit muscular contraction response developed by indirect stimulation or direct stimulation. The IC50 of indirect and direct stimulation were 0.28 mmol/L and 10 mmol/Lrespectively. The time required to inhibit 50% of the contraction by indirect stimulation was 4.3±1. 0 min. The inhibitory action could be antagonized partially by high Ca2+. Manganese could reduce the seusitivity of the chick biventer cervicis muscle to acetylcholine, and shift the dose-respond curves foracetylcholine to the right in a nonparallel manner with a pD2' value of 2. 62. The result suggested that manganese acted on pre- and post-synaptic sites.展开更多
文摘The effects of manganese on neuromuscular junction transmission were studied in the isolated rat phrenic nerve diaphragm preparation, chick biventer cervicis nerve-muscle preparation and toad rectus abdominis muscle preparation. It wa found that manganese could adversely andconcentration-dependently inhibit muscular contraction response developed by indirect stimulation or direct stimulation. The IC50 of indirect and direct stimulation were 0.28 mmol/L and 10 mmol/Lrespectively. The time required to inhibit 50% of the contraction by indirect stimulation was 4.3±1. 0 min. The inhibitory action could be antagonized partially by high Ca2+. Manganese could reduce the seusitivity of the chick biventer cervicis muscle to acetylcholine, and shift the dose-respond curves foracetylcholine to the right in a nonparallel manner with a pD2' value of 2. 62. The result suggested that manganese acted on pre- and post-synaptic sites.
