Avtor/Urednik		Melik, Ž
Naslov		Vpliv količine sproščenega mediatorja na časovni potek toka motorične ploščice
Tip		monografija
Kraj izdaje		Ljubljana
Založnik		Medicinska fakulteta
Leto izdaje		1993
Obseg		str. 52
Jezik		slo
Abstrakt		By recording the end-plate current the conductance change of the junctional membrane can be measured. Time course of the end-plate current is described by the rise time, amplitude and time constant of the falling phase. The time constant of the falling phase reflects the kinetics of the reactions between transmitter and receptors. It is very well known that after acetylcholinesterase inhibition the time constant of the end-plate current is longer the larger is the quantal content. This relation was studied in various species of experimental animals while acetylcholinesterase was fully active. Some results suggest there is no such dependence, but other indicate similar, although smaller dependence as while acetylcholinesterase is inactive. In the present study we performed experiments with paired stimuli to show whether the time constant of the end-plate current is longer if its quantal content is larger. Experiments were carried on frog nerve-muscle preparations at room temperature (20-23 degrees C) and at a lower temperature (6-l6 degrees C). To prevent contractions, muscles were glyceroltreated or curarized. In glycerol-pretreated muscles the time constant of decay is clearly dependent on the quantal content of the released transmitter. In the experiments on curarized muscles no such dependence was seen, possibly because of the different side - actions of curarine on neuromuscular transmission. It is concluded that, if acetylcholinesterase is active there is the possibility of repetitive binding of acetylcholine to the receptors.
Deskriptorji		MOTOR ENDPLATE ACETYLCHOLINESTERASE MEMBRANE POTENTIALS RANIDAE ANIMALS GLYCERIN TUBOCURARINE TEMPERATURE