The effect of lead on intracellular Ca(2+) in mouse lymphocytes.

Objective: Lead exposure is one of major public health problems. The aim of this study was to examine in vitro the effect of lead on lymphocyte intracellular Ca(2+) ([Ca(2+)]i).

Methods: Lymphocytes were separated from mice spleen and treated with three doses of PbCl(2) (1, 10 and 100 micromol/L). [Ca(2+)]i was measured in a Thermo Labsystems Fluoroskan Ascent after loading the cells with Fura2-AM probe.

Results: The lymphocyte [Ca(2+)]i in 10 and 100 micromol/L PbCl(2) groups increased to the highest level after 10 min of lead exposure (P<0.05). After 1h of lead exposure, however, lymphocyte [Ca(2+)]i levels were not statistically different from that in control group cells (P>0.05). Removal of Ca(2+) from external solution did not significantly affect the PbCl(2)-induced lymphocyte [Ca(2+)]i. PbCl(2) increased the [Ca(2+)]i under both normal Ca(2+) and Ca(2+)-free conditions. With pretreatment of calmodulin (CaM) antagonist W7, lymphocyte [Ca(2+)]i levels were still high, but [Ca(2+)]i levels were not as high as those in the absence of W7.

Conclusion: When the lymphocytes were exposed to PbCl(2) ranging from 1 to 100 micromol/L, the lymphocyte [Ca(2+)]i level was increased, but the increase appeared reversible(.) CaM may play a role in the process of the effect of lead on the lymphocyte [Ca(2+)]i.