NCIt definition : The bromide salt form of propantheline, a quaternary ammonium compound structurally
related to belladonna alkaloids. Propantheline bromide competitively antagonizes acetylcholine
activity mediated by muscarinic receptors at neuroeffector sites on smooth muscle
and exocrine gland cells. An aspartic acid residue present in the N-terminal portion
of the third trans-membrane helix of the muscarinic receptor is believed to form an
ionic bond with the tertiary or quaternary nitrogen of the antagonist. Antagonism
leads to a reduction of exocrine glands secretions and to relax bronchial muscle and
reduce tone and motility of intestinal smooth muscle.;
Semantic type(s)