D-Glutamic Acid-Induced Muscle Contraction in the Silkworm, Bombyx Mori

J Biochem. 2005 Feb;137(2):199-203. doi: 10.1093/jb/mvi019.


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.

MeSH terms

  • Animals
  • Bombyx / physiology*
  • Excitatory Amino Acid Agonists / pharmacology
  • Glutamic Acid / analysis
  • Glutamic Acid / pharmacology
  • Glutamic Acid / physiology*
  • Hemolymph / chemistry
  • Kainic Acid / antagonists & inhibitors
  • Kainic Acid / pharmacology
  • Larva / physiology
  • Muscle Contraction / drug effects
  • Muscle Contraction / physiology*
  • Muscles / drug effects
  • Receptors, Glutamate / drug effects
  • Receptors, Glutamate / physiology


  • Excitatory Amino Acid Agonists
  • Receptors, Glutamate
  • Glutamic Acid
  • Kainic Acid