PRODUCTION OF α-FETOPROTEIN BY CULTURED RAT ASCITES HEPATOMA CELLS DETERMINED IN VIVO AS α-FETOPROTEIN-NEGATIVE

Three ascites hepatoma cells of the rat, AH-41B, AH-34, and AH-64B, which had been determined in vivo as α-fetoprotein-negative, were cultivated in vitro in a medium containing adenosine 3', 5'-cyclic monophosphate (cyclic AMP), cyclic dibutyryl-AMP, or theophylline. The concentration of α-fetoprotein in culture media was measured by the 125I-radioimmunoassay. Results demonstrated that the AH-41B cells produced α-fetoprotein in vitro, the concentration of which being elevated in the media with three substances, while the remaining AH-34 and AH-64B cells did not. A comment was made on the producibility of α-fetoprotein in the so-called α-fetoprotein-negative hepatoma cells.