Action of taurine, 3-aminopropanesulfonic acid, and GABA on the hindgut and heart of the cockroach, Leucophaea maderae.
Taurine, glycine, glutamate, and gamma-aminobutyric acid (GABA) were all present in concentrations of greater than 1% of the total free amino acid content in the brain, thoracic, and abdominal ganglia of Leucophaea maderae. Hemolymph, subesophageal ganglia, and hindgut had substantial amounts of glutamate and glycine, but less than 0.3% taurine or GABA. Taurine, 3-aminopropanesulfonic acid (3-APS), cysteine-sulfinic acid (CSA), and GABA each had myotropic activity on the isolated cockroach hindgut, with 3-APS having the most consistent effect (ED50 = 0.63 mM), while taurine and CSA activities were similar to that of GABA on the hindgut. Both taurine and 3-APS had anti-arrhythmic effects on semi-isolated heart preparations of L. maderae, while GABA was inhibitory and induced arrhythmia. Bicuculline was antagonistic to the effects of GABA, taurine, and 3-APS on the hindgut, and induced arrhythmia in heart preparations; this arrhythmia was reversible by taurine, but not by GABA or 3-APS.
United States Department of Agriculture, Veterinary Entomology Unit, College Station, Texas.
R M
RM
Wagner
B J
BJ
Cook
J F
JF
Cooper
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D003058:Cockroaches / Q000502:physiology*; D004064:Digestive System / Q000187:drug effects; D004068:Digestive System Physiological Phenomena; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D018377:Neurotransmitter Agents / Q000032:analysis; D009928:Organ Specificity; D010852:Picrotoxin / Q000494:pharmacology; D013654:Taurine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D000596:Amino Acids; D001640:Bicuculline; D018377:Neurotransmitter Agents; D010852:Picrotoxin; D013654:Taurine; D005680:gamma-Aminobutyric Acid; C001355:tramiprosate