Effects of lead on calmodulin content, proliferation and interleukin-2 in lymphocytes of mice

Abstract

The mechanism inderlying lead (Pb)-induced toxicity was presumed to involve interaction between Pb²⁺ and calcium (Ca²⁺) associated with calmodulin-dependent systems. The aim of this study was to (1) examine the hypothesis that Pb alters calmodulin content and (2) assess the effects of Pb on proliferation and interleukin-2 (IL-2) levels in lymphocytes. The influence of Pb on calmodulin content in mouse lymphocytes was assessed by western blot, while the proliferation of lymphocytes was studied using MTT test, and IL-2 level by ELISA assay. The results showed that 100 µM PbCl₂ decreased calmodulin content, phytohemagglutinin (PHA)-induced proliferation, and IL-2 levels, but a lower concentration (1 µM PbCl₂) did not appear to be effective. Evidence indicates that IL-2 levels and lymphocyte proliferation might not be calmodulin content dependent. Our data suggested that Pb²⁺-induced toxicity was likely to be complex with multiple factors involved, including calmodulin, IL-2, and proliferation of lymphocytes.

Keywords:

• lead
• lymphocyte
• calmodulin
• cell proliferation
• interleukin-2

Acknowledgments

We thank Zhou Xielai for technical assistance with the cell culture. This work was financially supported by Zhejiang Natural Science Fundation (Grant Y204334).