D-Glutamic acid-induced muscle contraction in the silkworm, Bombyx mori.
Agonists for muscle contraction in silkworms were screened by injecting test solutions into the hemolymph of decapitated silkworm larvae. Kainic acid, a glutamate receptor agonist, and D-glutamic acid induced muscle contractions, and D-aspartic acid was partially effective, whereas NMDA and AMPA, representative mammalian glutamate receptor agonists, did not induce contraction. L-Glutamic acid inhibited the kainic acid or D-glutamic acid-induced contraction. Amino acid analysis revealed that 3% of the total glutamic acid in the silkworm hemolymph is D-glutamic acid. These results suggest that d-glutamic acid acts physiologically as an agonist for muscle contraction in silkworms, and that L-glutamic acid functions as an inhibitor.
Sekimizu
Kazuhisa
K
Graduate School of Pharmaceutical Sciences, The University of Tokyo, 3-1 Hongo 7-chome, Bunkyo-ku, Tokyo 113-0033. sekimizu@mol.f.u-tokyo.ac.jp
Larranaga
Jorge
J
Hamamoto
Hiroshi
H
Sekine
Masae
M
Furuchi
Takemitsu
T
Katane
Masumi
M
Homma
Hiroshi
H
Matsuki
Norio
N
D000818:Animals; D012831:Bombyx / Q000502:physiology*; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000032:analysis / Q000494:pharmacology / Q000502:physiology*; D006458:Hemolymph / Q000737:chemistry; D007608:Kainic Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology; D007814:Larva / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D009132:Muscles / Q000187:drug effects; D017470:Receptors, Glutamate / Q000187:drug effects / Q000502:physiology
D018690:Excitatory Amino Acid Agonists; D017470:Receptors, Glutamate; D018698:Glutamic Acid; D007608:Kainic Acid