[The postsynaptic effects of substance P in the frog neuromuscular synapse].
The effect of substance P on the end-plate currents (EPC) and miniature EPC (MEPC) was studied in the "cut" sartorius muscle of the frog using voltage-clamp technique after acetylcholinesterase inhibition. Substance P in the concentration 5.10(-7)-1.10(-6) mol/l had no effect on the amplitude and time course of the single EPC and MEPC, but promoted significant prolongation of EPC decay during repetitive nerve stimulation (10/s), which indicated development of postsynaptic potentiation. Elevation of the substance P concentration to 5.10(-6) mol/l has led to the shortening of single EPS decay and more significant depression of the EPC amplitude in trains. This effect was connected with a decrease of the postsynaptic membrane sensitivity to acetylcholine, i. e. development of desensitization.
Giniatullin
R A
RA
Zefirov
A L
AL
Magazanik
L G
LG
Oshchepkova
S F
SF
D000818:Animals; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009045:Motor Endplate / Q000187:drug effects / Q000502:physiology; D009388:Neostigmine / Q000494:pharmacology; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000502:physiology; D011895:Rana ridibunda; D017981:Receptors, Neurotransmitter / Q000187:drug effects* / Q000502:physiology
D002800:Cholinesterase Inhibitors; D017981:Receptors, Neurotransmitter; D009388:Neostigmine
Postsinapticheskie éffekty substantsii P v nervno-myshechnom sinapse liagushki.