Physiochemical Effects of Electrically Induced Convulsions

Abstract

Following the convulsions in dogs, the electrolyte content (conductivity) of the cerebrospinal fluid (CSF), the total interferometric values (IV) and the ratio of the interferometric value of non-electrolytes (INE) to that of the electrolytes (IE) were increased. Particularly the increase of the IV value and of the [image] ratio were sta- IE tistically significant. The average increase of phosphates was 18.5%, that of K 21.5%, within one hour after the last convulsions (group I), while 1-3 days after the last convulsion (group II), the increase of phosphates was 1.3%, that of K 11.2%. Expts. on isolated surviving frog''s brains showed a definite increase in the conductivity, and thus in the ion concn. of the bathing fluid during and 1 min. after stimulation. This increase of leakage from the brain on stimulation is at least partly due to diffusion of K as shown by detns. of K in the bathing fluid. Regarding the non-electrolytes, an increase of the ratio [image] by 4.1% was found within the 1st hr. following the convulsions (group I). In the following days, the ratio [image] further increases (6.8% in group II). Studies of the permeability of the blood-liquor barrier by means of the uranine test indicated that an increased permeability of the blood-liquor barrier is not responsible for the increase of non-electrolytes. An abnormal content in glucose and proteins also could be excluded. Using Hauptmann''s saponin hemolysis test as an indicator of lipides, a slight increase of the inhibitory effect upon saponine hemolysis as compared with normal spinal fluids was found following convulsions only occasionally. In spectrophotometric studies, the CSF''s of dogs subjected to convulsions showed band absorption between wave length 2,550 and 2,850 A. This absorption band probably is due to abnormal amts. of nucleic acids or their constituents, belonging to the pyrimidine-purine group. Microchemically, traces of thymonucleic acid were detected in the CSF following the convulsions. These findings suggest breakdown of nuclear substances under the influence of the convulsions.