Penicillin-induced convulsions have preferential effects on transmitter glutamate pools in rat neostriatum

Repeated penicillin-induced amygdala epileptic focus in freely moving cats. EEG, polysomnographic (23-h recording), and brain mapping study

The effect of repeated Na-penicillin (PCN) microinjections in the temporal lobe amygdala (AM) of free-moving cats was investigated in order to establish if kindling epileptogenesis is possible with this procedure. The cortical propagation of the PCN-induced post-discharge in AM and the sequence of behavioral changes induced by PCN were similar to those of AM electrical kindling. Nevertheless, the epileptogenic effect of PCN had a different evolution from that of electrical kindling, since some PCN habituation was observed after several doses. Repeated microinjections of PCN did not produce lasting alterations in sleep onset and organization. The only mild changes recorded in the 23 h following PCN microinjections were an increased latency of the first rapid eye movement (REM) sleep episode, a SWS II total time and percentage increase, and, with the highest PCN doses, a not very significant diminution of REM sleep total time. Another finding was the occurrence of REM sleep ponto-geniculo-occipital (PGO) waves, coinciding with a depression of the frequency and amplitude of interictal amygdaloid and cortical spikes. The results showed that a microinjection of PCN in the AM produced a reliable model of interictal spikes, paroxysms and generalized convulsive seizures. Nevertheless, long lasting kindling effect was not observed.

Evidence for one-electron oxidation of benzylpenicillin G by lactoperoxidase compounds I and II

The ability of the widely used antibiotic benzylpenicillin G to undergo a peroxidatic oxidation to produce free radical species has been investigated using conventional spectrophotometry, rapid scan spectrophotometry and an ESR spin trapping technique. Lactoperoxidase was used as a model for a drug oxidizing system. The results of the investigation indicate a normal peroxidatic pathway of benzylpenicillin degradation which leads to superoxide radical generation.