Electrical effects of histamine on monolayers formed in culture from enriched canine gastric chief cells.
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 approximately equal to 36 hr. Immunofluorescence with an antipepsinogen I antibody revealed pepsinogen-containing granules in greater than 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) of 26 +/- 4 mV (apical surface negative), a short-circuit current (Isc) (+/- SEM) of 16 +/- 2 microA/cm2, and a transepithelial resistance (R) (+/- SEM) of 1,480 +/- 210 omega X cm2. Histamine increased the short-circuit current, an effect blocked by an H2-receptor antagonist. Seventy percent of the spontaneous PD was amiloride sensitive, suggesting sodium 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 greater than 48 hr in culture, thus allowing study of oriented functions of a selected cell type. The present studies indicate that 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.
D000818:Animals; D002469:Cell Separation; D002478:Cells, Cultured; D004285:Dogs; D004553:Electric Conductivity; D005455:Fluorescent Antibody Technique; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D006632:Histamine / Q000494:pharmacology*; D008564:Membrane Potentials; D008854:Microscopy, Electron; D010435:Pepsinogens / Q000378:metabolism
D010435:Pepsinogens; D006632:Histamine