ABSTRACT
The mRNA expression levels of Ca²âº transporter genes including the epithelial calcium channel (ECaC), sodium/calcium exchanger 1b (NCX1b), and plasma membrane calcium ATPase 2 (PMCA2) were measured in zebrafish larvae after exposure to 0.08 µM Cd²âº in either water mixed with 0.2 mM Ca²âº (lCa) or 2 mM Ca²âº (hCa). The ECaC and NCX1b expression decreased at the 48 and 72 h mark, respectively; however, PMCA2 transcripts decreased at 96 h after exposure to Cd²âº in lCa environment. On the other hand, the ECaC transcripts were not affected; however, the PMCA2 transcripts were increased at 72 h, while the NCX1b transcripts significantly decreased at 48 and 96 h after exposure to Cd²âº in a hCa environment. The Ca²âº contents of larvae significantly decreased after Cd²âº exposure in a lCa environment; however, the Ca²âº contents were evidently higher after exposure to Cd²âº in a hCa environment, except for 48th h mark. In addition, ECaC morphants showed lower Ca²âº contents of whole-body, and there were higher levels of mortality after exposure to the same condition compared to the wild-type groups. In contrast, injection of ECaC cRNA resulted in an increase in Ca²âº content and the rate of Ca²âº influx in zebrafish embryos. Summary, the results showed that the Ca²âº transporters of zebrafish larvae were impacted after exposures of 0.08 µM Cd. However, in the exposure condition, the ECaC and PMCA2 transcripts could be restored to control levels after the fish were treated in an environment with hCa.
