Stumbled onto this. Lysine potentiates diazepam and appears to be GABAergic (?).
Source: http://www.springerlink.com/content/g5245284836123x8/
edit: clean up
Source: http://www.springerlink.com/content/g5245284836123x8/
Our earlier observations showed that l-lysine enhanced the activity of diazepam against seizures induced by pentylenetetrazol (PTZ), and increased the affinity of benzodiazepine receptor binding in a manner additive to that caused by gamma-aminobutyric acid (GABA). The present paper provides additional evidence to show thatl-lysine has central nervous system depressant-like characteristics.
l-lysine enhanced [3H]flunitrazepam (FTZ) binding in brain membranes was dose-dependent and stimulated by chloride, bromide and iodide, but not fluoride. Enhancement of [3H]FTZ binding byl-lysine at a fixed concentration was increased by GABA but inhibited by pentobarbital between 10–7 to 10–3M. While GABA enhancement of [3H]FTZ binding was inhibited by the GABA mimetics imidazole acetic acid and tetrahydroisoxazol pyridinol, the enhancement by pentobarbital andl-lysine of [3H]FTZ binding was dose-dependently increased by these two GABA mimetics. The above results suggest that l-lysine and pentobarbital acted at the same site of the GABA/benzodiazepine receptor complex which was different from the GABA binding site.
The benzodiazepine receptor antagonist imidazodiazepine Ro15-1788 blocked the antiseizure activity of diazepam against PTZ. Similar to pentobarbital, the anti-PTZ effect of l-lysine was not blocked by Ro15-1788. Picrotoxinin and the GABA, receptor antagonist bicuculline partially inhibitedl-lysine''s enhancement of [3H]FTZ binding with the IC50s of 2 mgrM and 0.1 mgrM, respectively. The convulsant benzodiazepine Ro5-3663 dose-dependently inhibited the enhancement of [3H]FTZ binding byl-lysine. This article shows the basic amino acidl-lysine to have a central nervous system depressant characteristics with an anti-PTZ seizure activity and an enhancement of [3H]FTZ binding similar to that of barbiturates but different from GABA.
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