Inhibitory effects of exogenously applied met-enkephalin on submandibular ganglion cells.
In this study, effects of exogenously applied Met-enkephalin on hamster submandibular ganglion cells were investigated using an intracellular recording technique. Met-enkephalin (10 microM) was applied to cells by pressure ejection (2 kg/cm2, 50 msec) from a micropipette. More than 30% of the cells caused a hyperpolarization (amplitude: about 3 mV) accompanied by an increase in potassium conductance. After 30-40 ejections, the Ca2+ spike was shortened by 18.1%, and the nicotinic transmission was depressed. The inhibitory effect on presynaptic terminals was blocked by naloxone (10 microM).
Suzuki
T
T
Department of Physiology, Tokyo Dental College, Japan.
Endoh
T
T
D000200:Action Potentials; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D006224:Cricetinae; D004744:Enkephalin, Methionine / Q000037:antagonists & inhibitors / Q000494:pharmacology* / Q000502:physiology; D005726:Ganglia, Parasympathetic / Q000166:cytology / Q000187:drug effects*; D008564:Membrane Potentials / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000819:agonists; D013363:Submandibular Gland / Q000294:innervation*; D009435:Synaptic Transmission / Q000187:drug effects*
D002121:Calcium Channel Blockers; D015221:Potassium Channels; D009270:Naloxone; D004744:Enkephalin, Methionine; D011188:Potassium; D002118:Calcium