Metallothionein expression and pregnancy outcomes in Helicobacter pylori infected pregnant mice, their foetuses and pups

Abstract

Metallothionein (MT), a metal-binding ligand, has been demonstrated to sequester reactive oxygen species and H. pylori infection have been associated with increased ROS production, which has been linked to adverse pregnancy outcomes. This study investigates the relationship between MT expression and pregnancy outcomes in H. pylori infected pregnant mice. Female C57BL/6 mice were inoculated with 108 H. pylori (n=18) or water (n=18) via gavage. After 6 wk, mice were mated and 2 wk after impregnation, 9 mice from each group were sacrificed and foetus weight and litter size were recorded. The remaining mice were allowed to give birth and litter size and pup weights were recorded. A third of all pups were sacrificed at d 1, 11, and 28 after birth, respectively and mothers were also sacrificed. The stomach, small intestine and liver were removed and assayed for MT using the 109Cd-haem affinity assay. H. pylori load was determined by culture. H. pylori infection did not alter MT levels during pregnancy compared to controls. Foetal MT levels (5.3±1.3 nmol Cd bound/g wet weight) of infected mother was significantly (p<0.05) higher compared to controls (2.7±0.5). No differences in stomach, small intestine and liver MT of d 1, 11 and 28 pups of infected or control mothers. Stomach MT of infected mothers (8.0±0.5) was significantly (p<0.05) decreased compared to controls (11.8±1.0) and no differences were seen in the small intestine and liver. MT expression in pregnant mice and their pups was not affected by H. pylori. Increased foetal MT levels may prevent small foetuses and reduced litter size in infected pregnant mice.