| Abstract: | Tests were carried out on the smooth-muscle cells (SMC) of the anococcygeus muscle of rats and rabbits by the double  sucrose gap method with Krebs' solution containing tetraethylammonium (1 mmole/liter). Stimulation of a muscle strip from the anococcygeus of rats and rabbits by square pulses of maximal amplitude and short duration induced excitatory postsynaptic potentials (EPSPs) in rat and rabbit SMC and inhibitory postsynaptic potentials (IPSPs) in rabbit SMC. The amplitude of the postsynaptic potentials was a linear function of the membrane potential. Removal of chlorine ions from the external solution reduced the amplitude of EPSPs of SMC of the rabbit anococcygeus and shifted the reversal potential toward the sodium equilibrium potential. EPSP generation in SMC of the rabbit anococcygeus is evidently connected with an increase in membrane permeability to both sodium and chlorine ions.Department of Neuromuscular Physiology, A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. (Presented by Academican of the Academy of Medical Sciences of the USSR N. N. Gorev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 913–916, August, 1976. Original article submitted July 11. |
