Transplacental transfer of melamine

ObjectiveTo characterize transplacental transfer of melamine and related mechanisms as well as toxicity using human placental perfusion and cultured cells.MethodsTransfer and toxicity were analyzed in 4-h perfusions with 10 μM or 1 mM melamine, or 10 μM melamine with 10 nM cyanuric acid (CYA). Efflux transporters were studied in accumulation assay and toxicity in BeWo cells by MTT assay.ResultsOf added melamine 34–45% was transferred to fetal circulation and CYA made no difference. Histology, hCG production, and PLAP activity indicated functionality of placental tissue with no grave toxicity. Highest concentration of melamine used (2 mM) with CYA and long treatment time decreased viability of BeWo cells. Inhibitors of ABCB1, ABCG2, ABCC2 did not affect the accumulation of melamine in cells.ConclusionMelamine goes through human term placenta with no contribution of efflux transporters. Toxicity of melamine is low in placental tissue and BeWo cells.