Substance P-induced depolarization accompanied by a decrease in membrane input resistance in the hamster submandibular ganglion cell.
We described in a previous paper (Bull Tokyo dent Coll 33: 33-35, 1992) that the submandibular ganglion cells (SMG) of hamster responded to substance P (SP) with a depolarization, which could be divided into three subtypes according to the change in membrane input resistance (Rm) during depolarization: depolarizations accompanied by either an increase or a decrease in Rm, and without change in Rm. In this study, the generation mechanism of the SP-induced depolarization accompanied by a decrease in Rm was investigated using the current-clamp technique. The result showed that cation channels coupled with NK-1 receptors on SMG cells were involved in generation of the SP-depolarization, and that the main charge carrier was the sodium ion.
Soejima
T
T
Department of Physiology, Tokyo Dental College, Chiba, Japan.
Endoh
T
T
Suzuki
T
T
D000818:Animals; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D017097:Electric Impedance; D004594:Electrophysiology; D005726:Ganglia, Parasympathetic / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D018408:Patch-Clamp Techniques; D018040:Receptors, Neurokinin-1 / Q000819:agonists / Q000378:metabolism*; D015222:Sodium Channels / Q000378:metabolism*; D013373:Substance P / Q000494:pharmacology*; D015320:Tachykinins / Q000502:physiology
D018040:Receptors, Neurokinin-1; D015222:Sodium Channels; D015320:Tachykinins; D013373:Substance P