Mobiloization of intracellular calcium ions in chicken and rat lymphocytes induced by T cell mitogens

摘要

Cytosolic Capo is known to be an important factor in intracellular signaling pathways that regulate several cellular functions. The present study was designed to measure the intracellular concentrations of Capo ([Capo]i) in T cell mitogen-stimulated chicken lymphocytes, and to compare the results with those in rat lymphocytes. [Capo]i was increased in the thymocytes, splenocytes and bursacytes of chickens, and in the thymocytes and splenocytes of rats following exposure to the mitogens phytohaemagglutinin (PHA) and concanavalin A (ConA). Increases were greatest in the thymocytes followed by the splenocytes and bursacytes. The PHA-induced changes in the thymocytes and splenocytes were similar in chickens and rats, but the ConA-induced increases were significantly lower in the chickens than rats. Pretreatment with EGTA before the application of PHA and ConA completely suppressed the rise in [Capo]i in all the chicken lymphocytes, indicating that the increases that occurred in PHA- and ConA-treated chicken lymphocytes could be entirely attributed to the influx of extracellular Capo. On the other hand, the PHA- and ConA-induced increase in [Capo]i in rat lymphocytes was not completely suppressed by EGTA, indicating the recruitment of Capo from the intracellular Capo pool. The results suggest species differences in the Capo-based responses to T cell mitogens between chicken lymphocytes and rat lymphocytes.