Examination of the metabolism of oedematous brain tissue. IV. The influence of carbon dioxide, bicarbonate and pH on respiration and aerobic glycolysis of normal and oedematous rabbit brain in vitro

Sodium nitroprusside (NPS) stimulates the lactate formation and causes intracellular electrolyte shifts in brain slices

Nitroprusside sodium (NPS) was added to slices from grey and white rabbit brain matter. The respiration, consumption of glucose, formation of lactate and pyruvate, water content, size of the extracellular space, and total and intracellular sodium and potassium concentrations were determined and calculated. 0.5 and 1 mM NPS stimulated the glycolytic glucose breakdown, and inhibited the respiration of grey and white slices. The respiration of white matter slices was stimulated by 0.05 and 0.01 mM NPS. The total and intracellular potassium concentrations in slices from grey and white matter were lowered markedly by 1 mM NPS. The total and the intracellular sodium concentrations in grey brain matter slices became higher in the presence of 1 mM NPS. A warning is given against uncritical clinical use of higher concentrations of NPS.

Examination of the metabolism of oedematous brain tissue. V. The metabolism of oedematous white matter from rabbit brain

Glucose and gas metabolism as well as water, sodium, and potassium content of normal and oedematous white matter slices of rabbit brain have been determined. A cutting technique for the preparation of the slices is described. Although the increase of the relative water content in oedematous white matter is much more pronounced than in oedema of the grey matter, we observed only one significant change: the pyruvate production in vitro is about 20% higher in slices prepared from oedematous brain.

Lactate dehydrogenase (LD), hydroxybutyrate dehydrogenase (HBD), and LD-isoenzymes in brain tissue

The total activities of lactate dehydrogenase (LD) and hydroxybutyrate dehydrogenase (HBD), and the LD isoenzyme distribution were determined in tissue samples taken in vivo from different parts of the rabbit brain, and in cortical grey, subcortical white, and cerebellar tissue from man. The total LD and HBD activities were found to be higher in the brain stem than in the cerebral hemisphere, basal ganglia, and cerebellum of the rabbit brain. The isoenzyme distribution in the brain stem and the cerebellum showed an anodal shift, i.e., significantly higher activities of LD1 compared with the cerebral hemisphere and the basal ganglia. In man the total LD activity was found to be lower in white than in grey matter, although the isoenzyme patterns did not differ. The implications of these findings in relation to the LD isoenzyme pattern in serum after traumatic brain injury are discussed.