Tumor necrosis factor reduces the ACh-induced outward current in identified Aplysia neurons.
Effects of extracellularly applied recombinant human tumor necrosis factor (rhTNF) on the acetylcholine (ACh)-induced K+ current recorded from identified neurons (R9 and R10) of Aplysia kurodai were investigated with conventional voltage-clamp and pressure ejection techniques. Bath-applied rhTNF (200-500 U/ml) reduced the ACh-induced current in the neurons without affecting the holding current and resting membrane conductance. The suppressing effect of rhTNF on the current was completely reversible. Inhibition by rhTNF was non-competitive. Heat-inactivated rhTNF was without effect. Our results suggest that the immunomodulator TNF can act on the ACh receptor in the nervous system.
Sawada
M
M
Department of Physiology, Shimane Medical University, Izumo, Japan.
Hara
N
N
Maeno
T
T
D000109:Acetylcholine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D000818:Animals; D001048:Aplysia / Q000378:metabolism*; D005724:Ganglia / Q000166:cytology / Q000187:drug effects; D007375:Interleukin-1 / Q000096:biosynthesis; D007473:Ion Channels / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007375:Interleukin-1; D007473:Ion Channels; D015221:Potassium Channels; D014409:Tumor Necrosis Factor-alpha; D000109:Acetylcholine