130 REGULATION OF CALCIUM TRANSPORT CHANNELS IN THE DUODENUM, KIDNEY, AND PLACENTA OF A CATECHOL-O-METHYLTRANFERASE-INHIBITED MOUSE MODEL

Abstract

Preeclampsia is a pregnancy-specific disease characterised by concurrent development of hypertension, proteinuria, and oxidative stress in the placenta. Preeclampsia-like genetic models were also developed by modification of preeclampsia-related genes, such as catechol-O-methyltranferase (COMT). To investigate the pathophysiological conditions associated with preeclampsia, we divided pregnant mice into 4 groups (n = 20): vehicle, COMT inhibitor, vehicle plus 2% supplemental calcium diet, and COMT inhibitor plus 2% supplemental calcium diet. The pregnancy mice were treated with the specific COMT inhibitor (ro41–0960, 2.5 mg kg^–1) from gestation Day 15 to 19. In parallel with treatment, the pregnant mice were fed with the 2% supplemental calcium diet or the normal diet for 5 days. All mice were sacrificed at 24 h after last injection. Total RNA was extracted using Trizol regent according to the manufacturer's instructions. Using a quantitative reverse transcription-PCR (RT-qPCR), we measured the mRNA levels of several calcium transporters (TRPV5, TRPV6, PMCA1, and CaBP-9k) in the placenta, duodenum, and kidney. Placental TRPV5, TRPV6, and PMCA1 mRNA was significantly reduced by the COMT inhibitor, and the reduced PMCA1 mRNA was restored by calcium supplementation. Duodenal TRPV5, TRPV6, and PMCA1 mRNA was decreased in the COMT-inhibited mice, and slightly recovered after calcium supplementation. Although renal TRPV5, TRPV6, and PMCA1 mRNA was also decreased by COMT inhibition, their expression were regained by calcium supplementation compared with those of the control group. Taken together, these results indicate that physiological changes of the response to COMT inhibitor were similar to symptoms of preeclampsia, which may be related to disturbance of calcium metabolism during pregnancy. All statistical analyses were performed using Graphpad software (GraphPad, San Diego, CA, USA).