EFFECT OF ONE HYPERBARIC OXYGEN-INDUCED CONVULSION ON CORTICAL POLYAMINE CONTENT IN 2 STRAINS OF MICE

In rat striatum, after one hyperbaric oxygen (HBO)-induced convulsion, polyamine changes are found that could promote N-methyl-D-aspartate ( NMDA) activation. In the HBO-sensitive CD1 mouse, unlike in the common C57 strain, there is some support for NMDA activation after the HBO s eizure. We measured PA cortical content before and after the first HBO -induced convulsion (about 608 kPa O2) in CD1 and C57 strains. Putresc ine, spermidine and spermine were dansyl derivated and analysed by HPL C. Exposure to HBO significantly increased putrescine content only in CD1 though a similar trend was observed in C57. No further increase wa s observed after convulsion whatever the strain. There were no signifi cant changes in spermidine or spermine to support NMDA activation. The refore, putrescine increase in CD1 cortex could reflect the free radic al formation that is known to be greater in CD1 than in C57 mouse. Att empts to increase putrescine levels before HBO exposure hastened HBO-i nduced convulsion, less than spermidine or spermine. Because of physio logical polyamine interconversion, additionnal experiments with indire ct manipulation of putrescine levels and study of their time-course wo uld precise these preliminary reports on putrescine and HBO.