A rat parotid gland cell line, Par-C10, exhibits neurotransmitter-regulated transepithelial anion secretion

Because of the lack of salivary gland cell lines suitable for Ussing chamber studies, a recently established rat parotid acinar cell line, Par-C10, was grown on permeable supports and evaluated for development of transcellular resistance, polarization, and changes in short-circuit current (Isc) in response to relevant receptor agonists. Par-C10 cultures reached confluence in 3-4 days and developed transcellular resistance values of >/=2,000 Omega . cm2. Morphological examination revealed that Par-C10 cells grew as polarized monolayers exhibiting tripartite junctional complexes and the acinar cell-specific characteristic of secretory canaliculi. Par-C10 Isc was increased in response to muscarinic cholinergic and alpha- and beta-adrenergic agonists on the basolateral aspect of the cultures and to ATP and UTP (through P2Y2 nucleotide receptors) applied apically. Ion replacement and inhibitor studies indicated that anion secretion was the primary factor in agonist-stimulated Isc. RT-PCR, which confirmed the presence of P2Y2 nucleotide receptor mRNA in Par-C10 cells, also revealed the presence of mRNA for the cystic fibrosis transmembrane conductance regulator and ClC-2 Cl- channel proteins. These findings establish Par-C10 cells as the first cell line of salivary gland origin useful in transcellular ion secretion studies in Ussing chambers.