HISTAMINE AFFECTS GROWTH OF SHEEP RUMINAL EPITHELIAL-CELLS KEPT IN PRIMARY CULTURE

Ten, 100 and 1000 mu M histamine were applied to ruminal epithelial ce lls in primary culture. Each of these concentrations diminished cell c ount as well as the protein and DNA contents of cultures by approximat e to 20%. On Pappenheim staining, reduced cell count was predominantly attributable to a decrease in relatively chromophobic cells. It is co ncluded that histamine either induces apoptosis, or increases cell she dding, or interferes with mitosis and cell maturation. Each of these t hree possibilities implies that histamine may disturb epithelial regen eration after ruminal lactic acidosis.