Kinetics of Ca2+ uptake into lectin-induced secondary lymphocytes during reactivation with concanavalin A or...

The kinetics of Ca2+ uptake into lectin-induced secondary lymphocytes was studied during reactivation to DNA synthesis with concanavalin A (Con A) or interleukin 2 (IL-2). IL-2 did not cause any significant uptake of Ca2+ into the lymphocytes, while Con A induced an accumulation of Ca2+ into the lymphocytes which reached a maximum 1 to 2 h after the addition of the lectin. The time during which Ca2+ uptake occurred corresponded to the time of dependence on extracellular Ca2+ for lectin-induced DNA synthesis. The increased rate of Ca2+ accumulation and the shortened Ca2+ dependence period of secondary lymphocytes as compared with primary lymphocytes could explain the ability of secondary lymphocytes to display an accelerated response, in terms of DNA synthesis, to re-stimulus.