Membrane responses of the leech giant glial cell to the peptide transmitter myomodulin.
A myomodulin peptide has been suggested to mediate the response of the giant glial cells to stimulation of the Leydig interneuron in the central nervous system of the leech Hirudo medicinalis [Eur. J. Neurosci. 11 (1999) 3125]. We have now studied the glial response to the endogenous leech MM peptide (GMGALRL-NH(2), MMHir). The peptide evokes a membrane outward current (EC(50) approximately 2 microM), which neither desensitizes nor shows any sign of run-down, and elicits a K(+) conductance increase of the glial cell membrane. The peptidase inhibitor phenylmethylsulfonyl fluoride (PMSF) enhances the glial current response, suggesting the presence of endogenous extracellular peptidases.
Britz
Frank C
FC
Abteilung für Allgemeine Zoologie, FB Biologie, Universität Kaiserslautern, Postfach 3049, D-67653 Kaiserslautern, Germany.
Deitmer
Joachim W
JW
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000378:metabolism; D007865:Leeches / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009457:Neuroglia / Q000502:physiology*; D009479:Neuropeptides / Q000494:pharmacology / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000378:metabolism
D004791:Enzyme Inhibitors; D009479:Neuropeptides; D018377:Neurotransmitter Agents; C053302:myomodulin; D010447:Peptide Hydrolases