Abstract
Primary hepatocytes were cultured on collagen gel in serum-free, α-modified Eagle's minimum essential medium containing 0.1 μMinsulin, 0.1 μM dexamethasone, 10 mM pyruvate and supplements such as glucagon, epinephrine or growth hormone. The activities of alkaline phosphatase, 5' -nucleotidase and γ-glutamyltransferase were assayed in cell extracts prepared from the cultures. All three enzyme activities were induced by glucagon, epinephrine or dibutyryl cAMP.The maximally effective concentration of glucagon was 5-10 nM for both alkaline phosphatase and 5' -nucleotidase and 100 nMfor γ-glutamyltransferase. Only alkaline phosphatase activity was suppressed by growth hormone, which caused marked suppression at about 1 μU (0.25 ng)/ml. Taurocholate also induced both alkaline phosphatase and γ-glutamyltransferase activities at 1 mM.
