[The role of muscarinic cholinoreceptors in regulating cellular functional activity].

The modern concepts of the molecular mechanisms of the coupling of muscarinic receptors (m-ChR) with biochemical systems of effector cells are reviewed. The problem of m-ChR heterogeneity and a possible role of phosphoinositide and cyclase systems of "second messengers" generation in the mediation of the effects of agonists on m-ChR are discussed. Particular emphasis is given to the role of N-proteins in the regulation of the coupling of different m-Chr subtypes with the effector mechanisms.