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MUSCARINIC EXCITATION: A MICROELECTROPHORETIC STUDY ON CULTURED SMOOTH MUSCLE CELLS
Author(s) -
PURVES R.D.
Publication year - 1974
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1974.tb09689.x
Subject(s) - acetylcholine , muscarinic acetylcholine receptor , depolarization , intracellular , microelectrode , biophysics , chemistry , electrophysiology , contraction (grammar) , endocrinology , neuroscience , medicine , biology , electrode , biochemistry , receptor
1 Acetylcholine was applied iontophoretically to smooth muscle cells cultured from taeniae coli of new‐born guinea‐pigs. Responses were recorded with intracellular microelectrodes. 2 Acetylcholine induced depolarization, spike generation and contraction. Large conductance increases could be measured during the action of acetylcholine. 3 Injection of depolarizing currents through the recording electrode reversed the sign of potential responses. The reversal potential was −5 to −25 mV. 4 Minimum latencies of responses to acetylcholine were 120–500 ms. These values were not attributable to diffusion time. 5 Attention is drawn to the long latencies of a variety of muscarinic responses, and the suggestion made that muscarinic mechanisms as a class may be characterized by a long activation time.