Teratogen concentration changes as the basis of the heat stress enhancement of arsenate teratogenesis in hamsters.
Teratology 1986 Oct; 34(2):189-193
Production of teratogenic lesions in hamsters following continuous exposure to arsenate (7778394), in combination with short term maternal heat stress during the critical phase of organogenesis, was examined. On day six of gestation, four groups of Syrian-hamsters were implanted with either 0.321 or 0.482 molar (M) of radiolabeled sodium-arsenate (7778430). On day eight, of gestation, one group from each dose level was incubated at 39 degrees-C for 50 minutes. Rectal temperatures were determined for all animals before, during, and after hyperthermia treatment. Dams were sacrificed on day 13, and the fetuses recovered for examination. Increased plasma creatinine and urea concentrations in maternal blood drawn immediately following termination of heat treatment were noted; plasma levels of these compounds were not affected by arsenate concentrations. An elevation in maternal body temperature occurred during heat treatment, and subsided within 15 minutes posthyperthermia. Exposure to heat at both arsenic (7440382) dose levels produced increased concentrations of arsenic in maternal blood and placentas. Maternal blood arsenic levels in heat treated dams dropped to levels measured in nonheat treated dams within 2 or 3 hours post hyperthermia. Elevated placental concentrations of arsenic were prolonged relative to maternal blood levels, and remained elevated for a longer period of time in the 0.482M dose group. A higher percentage of litters with malformed fetuses was produced by heat treated dams. The authors conclude that in hamsters treated with arsenate and heat stressed during critical organogenesis, a rise in placental arsenic concentrations causes an increase in fetal malformations.
NIOSH-Publication; NIOSH-Grant; Rodents; Arsenic-compounds; Teratogenesis; Heat-treatment; Embryotoxicity
7778-39-4; 7778-43-0; 7440-38-2
Histology/embryology/genetics University of Pennsylvania School of Dental Medicine Philadelphia, PA 19104