title: L-glutamic acid, a possible neurotransmitter to anterior aorta of Aplysia.
abstract: The effect of L-glutamate on muscle fibers of the anterior aorta of the marine gastropod Aplysia are characterized. Iontophoretically applied L-glutamate depolarized anterior aorta muscle fibers in 14% of the applications; no response was detected in the other applications. Responses to iontophoretically applied L-glutamate desensitize rapidly and are antagonized by 2-amino-4-phosphonobutyric acid (2-APB). 2-APB also blocked excitatory junctional potentials (EJPs) in the anterior aorta. No significant response to D-glutamate was observed. These characteristics match those of L-glutamate at the arthropod neuromuscular junction. Bath-applied L-glutamate also depolarizes anterior aorta muscle fibers, by a mechanism clearly different from that of iontophoretically applied L-glutamate. Present results make L-glutamate a candidate neurotransmitter to molluscan circulatory muscles.
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology*; D001048:Aplysia / Q000502:physiology*; D004553:Electric Conductivity; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates / Q000494:pharmacology / Q000502:physiology*; D018698:Glutamic Acid; D007478:Iontophoresis; D018377:Neurotransmitter Agents / Q000502:physiology*
chemical_list: D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; D018377:Neurotransmitter Agents; D018698:Glutamic Acid