AUTORADIOGRAPHIC ANALYSIS OF DNA AND RNA SYNTHESIS IN THE NEONATAL RAT MAMMARY GLAND AFTER TRANSPLACENTAL EXPOSURE TO DIETHYLSTILBESTROL.
Item
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Title
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AUTORADIOGRAPHIC ANALYSIS OF DNA AND RNA SYNTHESIS IN THE NEONATAL RAT MAMMARY GLAND AFTER TRANSPLACENTAL EXPOSURE TO DIETHYLSTILBESTROL.
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Identifier
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AAI8401918
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identifier
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8401918
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Creator
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BERGMAN, BARBARA STERN.
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Contributor
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Elizabeth S. Boylan
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Date
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1984
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, General
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Abstract
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The administration of DES during pregnancy has been associated with benign and malignant changes in target tissues of the lower genital tract in humans and rodents. This study examined the effects of exposure to DES in utero on another estrogen target tissue, the mammary gland. Pregnant rats were injected with 1.2 (mu)g DES during the second (days 10 & 13) or third (days 15 & 18) week of pregnancy. Offspring were injected with either 3H-thymidine or 3H-uridine at 5 days of age. The second and fifth pairs of nipples were fixed, serially sectioned, and coated with NTB-3 liquid emulsion (Kodak). In the nipple hood, the upper and lower mammary duct, the upper and lower mesenchyme, and in the epithelium lateral to the nipple opening, number of grains was counted for uridine analysis and number of labeled cells was used for thymidine. The Mann-Whitney U Test was applied to these data. In 3H-thymidine injected pups exposed to DES in the second week, label uptake was reduced significantly (p < 0.05) in the upper and lower duct regions, while in the third week, no difference in labeling was found in any tissue examined. 3H-uridine labeled pups had reduced labeling in the upper and lower duct, the nipple hood, and the nipple epithelium after DES exposure during weeks 2 and 3. Mesenchyme did not incorporate much label in either experimental or control animals. This evidence of early inhibition of DNA and RNA biosynthesis is consistent with recent data showing a reduction in ductal branching after neonatal exposure to DES or estradiol in the mouse (Tomooka & Bern 1982).
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Biology
