The effects of Di (2‐ethylhexyl) phthalate (DEHP) on the electrical and mechanical properties of a cardiomyocyte network

Abstract

Di(2‐ethylhexyl) phthalate (DEHP) is a widely used plasticizer that is found in a variety of polyvinyl chloride (PVC) medical products. DEHP leaches from PVC tubing and has been linked to cancerogenic and adverse reproductive effects. Currently, little is known of the impact of phthalates on the heart. The effects of DEHP were examined by conducting in vitro experiments using confluent layers of neonatal cardiomyocytes. Exposure to 50ug/mL DEHP for 72‐hours led to a decrease in conduction velocity and asynchronous contractions. These effects were caused by a decrease in the presence of gap junctional connexin‐43 expression. DEHP treatment also affected the mechanical properties of the myocyte network, leading to an unusual type of cell motion. These findings were not attributed to modifications in cell‐cell adhesion, as changes in adherens junction and focal adhesion proteins were not significantly altered by DEHP treatment. Instead, the modified motion and was linked to changes within the underlying fibroblasts. The latter expressed significantly less triton‐insoluble vimentin, compared to control samples. Applicability of these findings to human patients remains to be established. Financial support by the American Heart Association, MidAtlantic Affiliate (0715335U) and the NIH (HL076722, HL087529) is gratefully acknowledged.