Differences in stimulus induced calcium increases in lacrimalgland acinar cells from normal and NZB/NZW F1 female mice

Abstract

Purpose. To compare the changes in intracellular free calcium in response to both cholinergic and adrenergic agonists in cells isolated from exorbital lacrimal glands of NZB/NZW F1 female mice (NZB/W) and normal Swiss Webster mice (SW). Methods. We have loaded cells with Fura-2 and measured total intracellular calcium using ratiomicrofluorometric methods. Isolated cells were also patch-clamped using perforated patch. Results. In all cells, both carbachol (CCh) and phenylephrine (PE) increased intracellular calcium. The calcium increase to both CCh and PE was less in cells from NZB/W animals than in cells from SW animals. In cells from young animals, the baseline calcium levels were the same, but in cells from older (6 months) NZB/W animals, the baseline levels of calcium were 50% higher than those seen in SW animals. Conclusion. These data suggest that cells from the NZB/W mice have different calcium dynamics, which could contribute to their compromised fluid secretion.