Effects of maternal restraint stress and sodium arsenate in mice

Abstract

Either maternal restraint stress or sodium arsenate treatment during pregnancy can cause adverse effects on the mouse conceptus. The current study assessed the effects of both factors administered concurrently. Five treatment groups were used initially: (1) vehicle (H 2O) control [C], (2) feed/water deprived [FWD], (3) sodium arsenate [SA], (4) restraint only [R], and (5) sodium arsenate plus restraint [SA + R]. A sixth group, arsenate plus feed/water deprived [SA + FWD], was added later, along with (7) a concurrent arsenate-only control [SAC]. Mated female CD-1 mice in groups 3, 5, 6, and 7 were injected ip with sodium arsenate (20 mg/kg) on gestation day (GD) 9 (plug = day 1). Group 5 mice were restrained for 12 h beginning immediately after dosing. Groups 4 and 5 were restrained in the supine position from 9:00 A.M. to 9:00 P.M. on GD 9; FWD mice were deprived during that time. All females were killed on GD 18 and subjected to teratologic examination. Significantly increased exencephaly and decreased fetal weight were seen in SA + R Group fetuses. The incidence of supernumerary ribs was significantly higher in the SA + R Group than in the SA Group but did not differ from the R Group. These results add to the evidence that maternal stress combined with a chemical teratogen may have a greater effect on the conceptus than would exposure to either agent alone.