title: Activation of substance P receptors leads to membrane potential responses in cultured astrocytes.
abstract: Cultured astrocytes from rat cortex and spinal cord responded with different types of membrane potential changes upon brief (10 seconds) applications of the natural neurokinin agonists substance P and neurokinin A. The most prominent type of response was a long-lasting membrane depolarization. In some cells, an initial rapid depolarization followed by a partial repolarization preceded the slow depolarizing event. Few astrocytes responded with a hyperpolarization of the membrane. Selective agonists at the NK-1 receptive site, substance P-methyl ester (SP-OME) and septide, mimicked the response to the natural neurokinins as did DiMe-C7, a selective NK-3 receptor agonist. A putative neurokinin antagonist, (D-Arg1,D-Pro2,D-Trp7,9,Leu11)SP (DADPDT) partially blocked membrane potential responses induced by substance P, SP-OME, septide, DiMe-C7, and NKA. The authors conclude that astrocytes express NK-1 and NK-3 receptors, which upon activation affect the electrical properties of these cells.
authors: E. Merck, Biological Research, Darmstadt, Federal Republic of Germany.
authors: M
authors: M
authors: Wienrich
authors: H
authors: H
authors: Kettenmann
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism / Q000502:physiology*; D001921:Brain / Q000166:cytology; D002478:Cells, Cultured; D008564:Membrane Potentials / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000502:physiology*; D013373:Substance P / Q000494:pharmacology* / Q000502:physiology; D015320:Tachykinins / Q000494:pharmacology* / Q000502:physiology
chemical_list: D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter; D015320:Tachykinins; D013373:Substance P