Effects of diacylglycerol and phorbol ester on acetylcholine release and action at the neuromuscular junction in mice.
Miniature endplate potentials and nerve-evoked endplate potentials were studied in a phrenic nerve-diaphragm preparation of the mouse. A phorbol ester, phorbol-12 beta, 13 alpha-dibutyrate, and a diacylglycerol, 1-oleyl-2-acetyl-sn-glycerol, both increased the frequency of miniature endplate potentials. The effect of the phorbol ester on the frequency was still significant when the preparation was incubated in a calcium-deficient solution. The phorbol ester, but not the diacylglycerol, caused a significant increase in the amplitude of the miniature potentials. The phorbol ester also increased the amplitude of the endplate potentials in the presence of (+)-tubocurarine. The mechanisms of action of phorbol ester and diacylglycerol are discussed in relation to the control of acetylcholine release and action at the neuromuscular junction.
Murphy
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RL
Smith
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D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D003964:Diaphragm / Q000294:innervation; D004075:Diglycerides / Q000494:pharmacology*; D004558:Electric Stimulation; D005989:Glycerides / Q000494:pharmacology*; D066298:In Vitro Techniques; D008274:Magnesium / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D009045:Motor Endplate / Q000187:drug effects*; D009469:Neuromuscular Junction / Q000187:drug effects*; D010293:Pargyline / Q000031:analogs & derivatives / Q000494:pharmacology; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000494:pharmacology*; D010704:Phorbols / Q000494:pharmacology; D010791:Phrenic Nerve; D013237:Stereoisomerism; D014403:Tubocurarine / Q000494:pharmacology
D001596:Benzylamines; D004075:Diglycerides; D005989:Glycerides; D010703:Phorbol Esters; D010704:Phorbols; C051794:N-propargylbenzylamine; D015240:Phorbol 12,13-Dibutyrate; C038237:1-oleoyl-2-acetylglycerol; D010293:Pargyline; D008274:Magnesium; D002118:Calcium; D014403:Tubocurarine; C033085:phorbol