sentences:  Such properties are characteristic of an [[antagonist]] of [[acetylcholine]] exerting its effects at [[nicotinic]], but not [[muscarinic]] sites.In the rat [[phrenic nerve-diaphragm]] preparation, for example, a 2 x 10−5M concentration of MLA produced a 50% decrease in response, and total inhibition was caused by a 3 x 10−5M concentration of the drug.In this preparation, MLA-treated muscle responded normally to "direct" electrical stimulation, but the inhibition of contractions was only partially antagonized by [[physostigmine]].