1992 年 17 巻 6 号 p. 377-384
Mature rat hepatocytes were cultured on collagen coated dishes in serum-free a-modified Eagle's minimum essential medium containing 0.1 μM insulin, 0.1 μM dexamethasone, 10 mM pyruvate and Ca2+ at concentrations of 0-2 mM. Survival of nondivided cells was best in medium containing 2 mM Ca2+. Proliferation during 5-day culture was greatest with 0.4 mM Ca2+, but DNA synthesis was scarcely affected by the concentration of Ca2+. Both the activities of alkaline phosphatase, 5 -nucleotidase, γ-glutamyltransferase and lactate dehydrogenase and the number of cell nuclei of cultures in 0.1 mM and 2 mM Ca2+ media were assayed over a 5-day period, and their activities were calculated as enzyme activities per unit number of cell nuclei. Alkaline phosphatase activity increased rapidly during the first day of culture in both media, and its activity in 0.1 mM medium was higher than that in 2 mM medium after culture for 3 days. The activity of 5'-nucleotidase became higher in 0.1 mM medium than in 2 mM medium from day 2 and was maximal on day 3 in both media. ϒ-Glutamyltransferase activity increased and lactate dehydrogenase activity decreased with time in culture, both activities showing no appreciable difference in the two media.
