GLOBAL POLLUTION PROBLEMS, TRENDS IN DETECTION AND PROTECTION Increasing CACNA1C expression in placenta containing high Cd level: an implication of Cd toxicity Laorrat Phuapittayalert 1,2 & Phisid Saenganantakarn 1 & Wisa Supanpaiboon 3 & Supaporn Cheunchoojit 4 & Wiphawi Hipkaeo 5 & Natthiya Sakulsak 1 Received: 21 April 2016 /Accepted: 4 October 2016 # Springer-Verlag Berlin Heidelberg 2016 Abstract Cadmium (Cd) has known to produce many ad- verse effects on organs including placenta. Many essential transporters are involved in Cd transport pathways such as DMT-1, ZIP as well as L-VDCC. Fourteen pregnant women participated and were divided into two groups: high and low Cd-exposed (H-Cd, L-Cd) groups on the basis of their resi- dential areas, Cd concentrations in the blood (B-Cd), urine (U- Cd), and placenta (P-Cd). The results showed that the B-Cd and U-Cd were significantly increased in H-Cd group (p < 0.05). Interestingly, the P-Cd in H-Cd group was elevated (p < 0.05) and positively related to their B-Cd and U-Cd values (p < 0.05). However, the mean cord blood Cd (C-Cd) concentration in H-Cd group was not significantly increased about 2.5-fold when comparing to L-Cd group. To determine the Cd accumulation in placental tissues, metallothionein-1A (MT-1A) and metallothionein-2A (MT-2A) expressions were used as biomarkers. The results revealed that mean MT-1A and MT-2A mRNAs and MT-1/2 proteins were up-regulated in H-Cd group (p < 0.05). In addition, the Ca channel alpha 1C (CACNA1C) mRNA and protein expressions were noticeably elevated in H-Cd group (p < 0.05). From these findings, we suggested that CACNA1C might be implicated in Cd trans- port in human placenta. Keywords Cadmium (Cd) . Placenta . Metallothionein (MT) . Calcium (Ca) . Calcium channel alpha 1C (CACNA1C) Introduction Placenta is an organ that is developed to support the fetal growth and development of fetus during pregnancy. It is con- stituted by both maternal and fetal portions. In the placental fetal portion, a structure named chorionic villus serves as a functional unit of placenta which plays the important roles for gas and nutrient exchange, hormone production, and protec- tion of the fetus from xenobiotic and toxic elements (Knipp et al. 1999; Gude et al. 2004; Donnelly and Campling 2008). Previous studies have demonstrated that cadmium (Cd), a tox- ic heavy metal, is accumulated in many organs such as the kidney, liver, as well as placenta (Sorkun et al. 2007; Kippler et al. 2010). Moreover, there were evidences that Cd caused morphological and functional changes of placenta in CdCl 2 - injected rodents. For instance, Cd induced degeneration of placental maternal portion and loss of fetal villi architecture, which resulted in deformities of embryo and finally intra- uterine death (Chiquoine 1965; Samarawickrama and Webb 1979). In human, high Cd-accumulated placentas were found in pregnant, who lived in Cd-contaminated area and who had smoking habit, (Bush et al. 2000; Kantola et al. 2000; Osman et al. 2000; Ronco et al. 2005; Kippler et al. 2010) which manifested its results in the morphological changes and low birth weight of neonates (Bush et al. 2000; Ronco et al. 2005; Sorkun et al. 2007; Kippler et al. 2010). Responsible editor: Philippe Garrigues * Natthiya Sakulsak natthiyak@nu.ac.th; nsakulsak@yahoo.com 1 Department of Anatomy, Faculty of Medical Science, Naresuan University, Phitsanulok 65000, Thailand 2 Department of Anatomy, School of Medical Science, University of Phayao, Phayao 56000, Thailand 3 Department of Biochemistry, Faculty of Medical Science, Naresuan University, Phitsanulok 65000, Thailand 4 Department of Public Health, Faculty of Science, Buriram Rajabhat University, Buriram 31000, Thailand 5 Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen 40000, Thailand Environ Sci Pollut Res DOI 10.1007/s11356-016-7841-4