Glycine inhibition of glutamate evoked-release of norepinephrine in the hypothalamus is strychnine-insensitive

Brain Res. 1994 Jul 4;650(1):70-4. doi: 10.1016/0006-8993(94)90208-9.

Abstract

The effects of glycine (GLY), D-serine (D-SER), kynurenic acid (KYN), and 7-Cl kynurenic acid (7-Cl KYN), on the evoked release of endogenous norepinephrine (NE) by L-glutamate (L-GLU) in rat hypothalamic slices was investigated. KYN (500 and 100 microM) and 7-Cl KYN (10 microM) blocked evoked release of NE by L-GLU (1 mM). The inhibitory effects of 100 microM KYN on evoked release of NE by L-GLU were reversed by 10 microM and 100 microM D-SER and, but not 10 or 100 microM GLY. When KYN was not present in the superfusate, superfusion with either 10 or 100 microM GLY alone simultaneously with 1 mM L-GLU blocked the evoked release of NE produced by L-GLU. The addition of strychnine (3 or 100 microM) to the superfusate did not block the inhibitory effects of 10 microM GLY on L-GLU-evoked NE release. These findings suggest that a novel strychnine-resistant GLY receptor is present in the rat hypothalamus.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Excitatory Amino Acid Antagonists / pharmacology*
  • Glycine / pharmacology*
  • Hypothalamus / drug effects*
  • Hypothalamus / metabolism
  • In Vitro Techniques
  • Male
  • Norepinephrine / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Strychnine / pharmacology*

Substances

  • Excitatory Amino Acid Antagonists
  • Strychnine
  • Glycine
  • Norepinephrine