title: Anticonvulsant properties of alpha, gamma, and alpha, gamma-substituted gamma-butyrolactones.
abstract: Derivatives of gamma-butyrolactone (GBL) substituted on the alpha- and/or gamma-positions were synthesized and tested for their effects on behavior in mice, on the electroencephalographs and blood pressure of paralyzed-ventilated guinea pigs, and on electrical activity of incubated hippocampal slices. Several compounds, including alpha-ethyl-alpha-methyl GBL (alpha-EMGBL), alpha, alpha-dimethyl GBL, alpha, gamma-diethyl-alpha, gamma-dimethyl GBL, and gamma-ethyl-gamma-methyl GBL, prevented seizures induced by pentylenetetrazol, beta-ethyl-beta-methyl-gamma-butyrolactone (beta-EMGBL), picrotoxin, or all three compounds in mice and guinea pigs but had no effect on seizures induced by maximal electroshock or bicuculline. Neither gamma-hydroxybutyrate (GHB) nor alpha-isopropylidine GBL had any anticonvulsant activity. The anticonvulsant alpha-substituted compounds had a potent hypotensive effect and antagonized the hypertensive effect of beta-EMGBL, alpha-EMGBL was tested in incubated hippocampal slices and was found to depress basal activity and antagonize excitation induced by beta-EMGBL. These  results demonstrate that alpha-alkyl-substituted GBL and, to a lesser extent, gamma-substituted derivatives are anticonvulsant agents and that their effects are strikingly different from those of GHB or beta-alkyl-substituted GBLs, which are epileptogenic. Possibly beta- and alpha-substituted GBLs act at the same site as agonists and antagonists, respectively.
mesh_terms: D015107:4-Butyrolactone / Q000494:pharmacology*; D000818:Animals; D000927:Anticonvulsants; D001522:Behavior, Animal / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography; D005071:Evoked Potentials / Q000187:drug effects; D005260:Female; D005663:Furans / Q000494:pharmacology*; D006168:Guinea Pigs; D006624:Hippocampus / Q000187:drug effects; D066298:In Vitro Techniques; D051379:Mice; D012640:Seizures / Q000517:prevention & control; D013329:Structure-Activity Relationship
chemical_list: D000927:Anticonvulsants; D005663:Furans; D015107:4-Butyrolactone