Effects of para-nonylphenol on 92 kDa gelatinase secretion by human peripheral lymphocytes and U937 cells in vitro

Much attention has focused on environmental estrogenic chemicals such as para-nonylphenol which disrupt various tissues via the estrogen receptor. We studied effects of para-nonylphenol on gelatinase secretion by human lymphocytes in vitro. para-Nonylphenol (0.05-50 microM) dose dependently suppressed 92 kDa gelatinase secretion. The suppressive effect of 25 and 50 microM para-nonylphenol was completely blocked by tamoxifen. We also studied the effects of para-nonylphenol (0.05-50 microM) on 92 kDa gelatinase secretion by human leukemia U937 cells. para-Nonylphenol suppressed 92 kDa gelatinase secretion in a dose-dependent manner. The suppressive effect of 50 microM para-nonylphenol was completely blocked by tamoxifen. Estradiol did not significantly suppress 92 kDa gelatinase secretion. Our results suggest that para-nonylphenol suppressed 92 kDa gelatinase secretion via the estrogen receptor, however, para-nonylphenol interacts with the estrogen receptor in a manner distinct from estradiol. As this assay system is simple and rapid, it may prove useful to evaluate toxic effects of para-nonylphenol on human blood cells.