Prostaglandins of the F series are extremely powerful growth factors for primary neonatal rat hepatocytes

Abstract

At low concentrations (i.e., 10 −12–10 −9 mol/l), PGF 1α and PGF 2α very intensely stimulated both the DNA-synthetic and mitotic activities of hepatocytes in 4-day-old primary cultures of neonatral rat liver. DNA replication was more intensely enhanced by PGF 2α than by PGF 1α, whereas mitotic activity was nearly equally affected by the two prostaglandins. On the whole, the growth-promoting activity of PGF 1α used by itself or in equimolar mixtures with other prostaglandins ( e . g ., A 1, E 1, etc .) mimicked that of arachidonic acid we previously reported (1). On a molar basis, PGF 2α by itself stimulated hepatocytes′ DNA synthesis is more powerfully than arachidonate did, and when used in equimolar mixtures with other prostaglandins was at least as potent as arachidonic acid. These observations establish prostaglandins of the F series as quite powerful commitment factors and, though by a lesser degree, also intracycle regulators for neonatal rat hepatocytes in primary culture. However, the understanding of the role(s) of prostaglandins of F and other series in the physiological control of hepatocytes′ proliferative activation must wait the clarification of their interaction(s) with other arachidonate derivative(s) and polypeptide growth factor(s) which also may be involved in the process.