Taurine and related compounds were applied to rat extensor digitorum longus muscle fibers in vitro, and the effects on membrane potential, cable parameters, component conductances and excitability were observed with microelectrodes. After 20 min in 60 mM taurine the fibers hyperpolarized and there were decreases in the latency of a rheobasic stimulus, the duration of the action potential and the maximum number of spikes elicited by depolarizing pulses. The effects of taurine on membrane resistance are attributed to a specific dose-dependent increase in membrane chloride conductance (G) with little or no effect on membrane potassium conductance. (Cl)Gamma-aminobutyric acid at 30-60 mM also produced a specific increase in G(Cl) but, unlike taurine it caused a significant depolarization. β-alanine or sucrose at 60 mM did not mimic any of the effects observed with taurine at this concentration. It was concluded that the actions of taurine and GABA on excitability can be explained by increases in G(Cl).
The action of taurine on chloride conductance and excitability characteristics of rat striated muscle fibers
CONTE, Diana;
1987-01-01
Abstract
Taurine and related compounds were applied to rat extensor digitorum longus muscle fibers in vitro, and the effects on membrane potential, cable parameters, component conductances and excitability were observed with microelectrodes. After 20 min in 60 mM taurine the fibers hyperpolarized and there were decreases in the latency of a rheobasic stimulus, the duration of the action potential and the maximum number of spikes elicited by depolarizing pulses. The effects of taurine on membrane resistance are attributed to a specific dose-dependent increase in membrane chloride conductance (G) with little or no effect on membrane potassium conductance. (Cl)Gamma-aminobutyric acid at 30-60 mM also produced a specific increase in G(Cl) but, unlike taurine it caused a significant depolarization. β-alanine or sucrose at 60 mM did not mimic any of the effects observed with taurine at this concentration. It was concluded that the actions of taurine and GABA on excitability can be explained by increases in G(Cl).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
