Activity and Isoenzyme Pattern of Lactate Dehydrogenase in Astroblasts Cultured From Brains of Newborn Mice

Lactate dehydrogenase activity and isoenzyme distribution was determined in primary cultures of astroblasts as a function of the culture period. The specific activity increased during this period with a peak value (1.91 ± 0.18μmol x min‐1 x mg‐1 cell protein) after 2 weeks in culture. The isoenzyme pattern changed during 3 weeks in culture towards a higher proportion of the H4 (LDH‐1) isoenzyme which is analogous to the in vivo pattern. Omission of serum with or without dBcAMP (0.5 mM) in the culture medium during the third week of culture further enhanced this prominence of the H4 isoenzyme. The specific activity (1.58 × 0.06 μmol x min‐1 x mg‐1 cell protein) of cultures grown in the presence of 0.5 mM‐dBcAMP and absence of serum was close to the activity in the adult brain.