Effects of growth factors and gut hormones on proliferation of primary cultured gastric mucous cells of guinea pig

Almost completely homogenous gastric mucous epithelial cells of guinea pigs were grown to confluence in the presence of 10% fetal calf serum (FCS). FCS, epidermal growth factor (EGF), and insulin significantly increased 5-bromo-2'-deoxyuridine (BrdU) uptake by the cells and EGF together with insulin increased the cells' [H-3] thymidine uptake. Basic fibroblast growth factor (bFGF) enhanced EGF-induced DNA synthesis by the cells, but vasoactive intestinal peptide (VIP), secretin, prostaglandin E(2) (PGE(2)), and dibutyryl cyclic AMP (dbcAMP) neither induced DNA synthesis nor enhanced the effect of EGF on DNA synthesis by the cells. Gastrin, cholecystokinin-octapeptide (CCK8), and carbamylcholine chloride (CCh) also did not enhance the effect of EGF on DNA synthesis. I-125-EGF, I-125-bFGF, and I-125-gastrin binding to the gastric mucous cells revealed the presence of high-affinity receptors for EGF and bFGF, but not for gastrin. Northern blot analysis showed the expression of EGF receptor mRNA, but not gastrin receptor mRNA. These results suggest that EGF, insulin, and bFGF may cooperatively regulate gastric mucous cell growth, but that gastrin and other gastrointestinal hormones do not have a direct stimulatory effect on mucous cell growth in the guinea pig.