Electrical effects of histamine on monolayers formed in culture from enriched canine gastric chief cells.

Abstract

To develop techniques for studying transport properties and secretory function of selected cell types in the gastric mucosa, separated fractions of dispersed canine fundic mucosal cells were placed in short-term culture to form epithelial monolayers. Cell fractions enriched in either chief, parietal or mucous cells were prepared by using counterflow centrifugation and were plated on type I collagen. An epithelial monolayer formed by .apprxeq. 36 h. Immunoflourescence with an antipepsinogen I antibody revealed pepsinogen-containing granules in > 95% of the cells, regardless of whether the monolayers were formed from the mucous chief or parietal cell-enriched fractions. Upon achieving confluency, chief cell monolayers were mounted in Ussing chambers to study their electrical properties. Under basal conditions, monolayers (n = 6) had a spontaneous potential difference (PD) (.+-. SEM [scanning electron microscopy]) of 26 .+-. 4 mV (apical surface negative), a short-circuit current (Isc) (.+-. SEM) of 16 .+-. 2 .mu.A/cm2 and a transepithelial resistance (R) (.+-. SEM) of 1480 .+-. 210 .cntdot. cm2. Histamine increased the short-circuit current, an effect blocked by an H2-receptor antagonist. Of the spontaneous PD, 70% was amiloride sensitive, suggesting Na absorption accounted for a major component of the PD. These preparative techniques yield highly enriched chief cell monolayers, which maintain morphological and functional cellular differentiation for > 48 h in culture, thus allowing study of oriented functions of a selected cell type. An H2 receptor enhances electrogenic ion transport in chief cell monolayers, indicating that histamine can act on fundic mucosal cells other than just parietal cells.