Gestation activity

Uniformly labeled C-8-D with a specific activity of 2.99 juc/mg was administered orally to pregnant females at 2 /xg/kg/day from 6-15 days of gestation. Three females were sacrificed on alternate days during days 6-20 of pregnancy. Triplicate samples of fetus, placenta, blood, brain, abdominal fat, and sartorius muscle were procured from each female. The samples were dissolved in 1 ml of Soluene (Packard Instruments) to which 15 ml of Aquasol were added. Each sample vial was counted for 30 min in a Nuclear Chicago Mark I liquid scintillation counter. 

Oral treatment of pregnant dams with 0.25 /xg (or more) /kg/day of 2,3,7,8-tetrachlorodibenzo-p-dioxin for 10 days during gestation resulted in adverse effects on rat development. No adverse effects were seen at the 0.125 ju,g/kg/day. When C-2,3,7,8-tetrachlorodibenzo-p-dioxin (2.99 fjLc/mg) was given at 2 /xg/kg/day there was activity, primarily in liver and to a lesser extent, in fat and brain. When a single oral dose of 200 /Ag/kg was administered on gestation days 16, 17, or 18 and was followed 6 hours later with tissue sampling, the label was also observed in the fetus and placenta. Placenta had approximately twice as much label as the fetus. 

The POMC protein is processed differendy in the anterior lobe than in the intermediate lobe. The intermediate lobe of the pituitary is mdimentary in adult humans, but it is active in human fetuses and in pregnant women during late gestation and is also active in many animal species. Processing of the POMC protein in the peripheral tissues (gut, placenta, male reproductive tract) resem-... 

Decreased fetal weight and increased fetal death were reported following single intravenous injection of pregnant rats with 241Am (activity level 90 pCi/kg or 3,330 kBq/kg) on gestation day 9 (Rommerein and Sikov 1986). The investigators indicated a tendency toward increased incidences of fetuses with anomalous ribs. 

Exchanges between bone and soft tissue stores of americium would be expected to be more rapid during periods of active bone metabolism such as infancy and childhood, pregnancy, and menopause. Thus, it is possible that, in humans, some of the maternal bone americium stores may be transferred to the fetus during gestation and may be incorporated into fetal bone during the development of the fetal skeleton. 

Therefore, higher degradation of EA under ultrasound was possible only after some gestation period of sonication, when sufficient active species were produced in the aqueous solution. 

PCB 126 dams given 0.01 or 0.02 mg/kg BW by gavage every second day from days 9-19 of gestation Reduction in litter size, body weight, and survival of sucklings delayed spontaneous movement and neuromuscular maturation. Dams and pups had reduced body weight, and increased cytochrome P-4501 A1 activity 25... 

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