Aminopeptidases of newborn bovine nasal turbinate epithelial cell cultures

Abstract

Newborn bovine nasal turbinate epithelial cell cultures were grown to confluent monolayers and characterized by electron and light microscopy. The passaged nasal turbinate cells retain some similar but not identical morphological characteristics (e.g., microvilli, cuboidal shape, dome formation, apparent mucin granules) exhibited by parent tissue. Morphological properties, however, were consistent with other nasal cell culture systems that have been used to elucidate transport and metabolic features of nasal mucosa. The activity of aminopeptidases in homogenates of the turbinate cell cultures was assayed with 4-methoxy-2-naphthylamides of leucine, alanine, and arginine as substrates. The observed pattern of hydrolysis, apparent kinetic parameters, and inhibition by typical aminopeptidase inhibitors, puromycin and bestatin, were consistent with reported characteristics of aminopeptidases associated with excised nasal epithelial cells. Results here form the basis for consideration of the continuous newborn bovine nasal turbinate epithelial cell line in examining the role of aminopeptidases in determining the metabolic fate of intranasally administered peptides and proteins.