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Effect of Maternal Treatment with Methylmercury on the Manifestation of Cleft Lip in CL/Fr Mice
Author(s) -
KAJIWARA Yuji,
INOUYE Minoru
Publication year - 1987
Publication title -
congenital anomalies
Language(s) - English
Resource type - Journals
eISSN - 1741-4520
pISSN - 0914-3505
DOI - 10.1111/j.1741-4520.1987.tb00689.x
Subject(s) - fetus , methylmercury , pregnancy , embryo , chloride , teratology , incidence (geometry) , medicine , chemistry , andrology , endocrinology , biology , genetics , physics , organic chemistry , selenium , optics
Abstract The interaction between methylmercury teratogenesis and manifestation of cleft lip and palate (CL(P)) of genetic origin was experimentally investigated in CL/Fr mice. Pregnant mice were given methylmercuric chloride orally on day 10 of pregnancy at doses of 5, 10, 15 and 20 mg/kg. Animals were put to death on day 18 of pregnancy and the fetuses were examined for malformations, especially facial anomalies. About 23% of fetuses manifested CL(P) in the control group. After maternal treatment with methylmercuric chloride, the incidence of fetuses with CL(P) did not remarkably change in groups of 5 mg/kg (about 30%) and 10 mg/kg (about 24%), but decreased significantly (p<0.01) in groups of 15 mg/kg (about 12%) and 20 mg/kg (about 12%). The average numbers of both early and late fetal deaths in the mercury‐treated groups were not significantly different from those in the control group (p > 0.05): This suggested that the decreased incidence of fetuses with CL(P) was not attributable to the preferential mortality of embryos with CL(P). The incidence of isolated cleft palate (CP) was about 1, 5,40 and 80% after maternal treatments of 5,10,15 and 20 mg/kg methylmercuric chloride, respectively, showing the distinct threshold. No significant difference in mercury concentration was observed among normal fetuses, fetuses with CL(P) and with CP within any dose group.