title: What confers specificity on glycine for its receptor site?
abstract: 1. The structural requirements for activation of the glycine receptor were studied in isolated ventromedial hypothalamic neurones of rats by use of a 'concentration-clamp' technique under single-electrode voltage-clamp conditions. 2. alpha-Amino acids (L-alpha-alanine, and D-alpha-alanine, and L-serine), and glycine-methylester, glycine-ethylester and beta-amino acids (beta-alanine and taurine) produced a transient inward Cl- current, which was similar to that induced by glycine. 3. The responses to individual alpha- and beta-amino acids were selectively antagonized by strychnine, but were not affected by bicuculline, picrotoxin or the taurine antagonist, TAG (6-aminomethyl-3-methyl-4H,1,2,4-benzothiadiazine-1,1-dioxide hydrochloride), suggesting that alpha- and beta-amino acids activate the same glycine receptor. 4. beta-Amino acids were slightly more potent than the alpha-amino acids in causing cross-desensitization of the glycine response. 5. From the results of the structure-activity analysis of the optical isomers of alpha-alanine, serine and cysteine, a tentative structure of the glycine receptor is proposed.
authors.affiliation: Department of Neurophysiology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Tokutomi
authors.forename: M
authors.initials: M
authors.lastname: Kaneda
authors.forename: N
authors.initials: N
authors.lastname: Akaike
mesh_terms: D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D004594:Electrophysiology; D005998:Glycine / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D018009:Receptors, Glycine; D017981:Receptors, Neurotransmitter / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D000596:Amino Acids; D018009:Receptors, Glycine; D017981:Receptors, Neurotransmitter; D005998:Glycine