R C Rumbaugh

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Female rats were treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in either corn oil or contaminated soil from the Minker site in Missouri. Eight doses ranging from 0.015 to 5 micrograms TCDD/kg were used in the corn oil group; the range was 0.015 to 5.5 micrograms TCDD/kg in the TCDD-contaminated soil group. Rats in a third group were given equal(More)
Soil environmentally contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was given by gavage to guinea pigs and rats. The development of a characteristic clinicopathologic syndrome in guinea pigs, the induction of aryl hydrocarbon hydroxylase in rats, and the presence of TCDD in the livers of both species show that TCDD in soil exhibits high(More)
Previous reports have demonstrated the presence of moderate to high affinity binding for androgens in the cytosol of livers from male rats. This binding was significantly lower in female rats or in immature rats of either sex. The hepatic androgen binding protein, which sedimented at approx. 4 S on sucrose density gradients, has been called a receptor which(More)
Previous studies discovered a second class of estrogen-binding proteins distinct from estrogen receptor which exhibited higher capacity, lower affinity (HCLA) binding properties. HCLA sites underwent postpubertal sex differentiation, such that adult male levels were at least 10-fold higher than adult female levels. Neonatal castration of male rats prevented(More)
Studies were carried out to investigate the mechanism(s) responsible for the changes in adrenal microsomal mixed function oxidase activity which occur with aging (30-200 days) in guinea pigs. With aging, the rate os metabolism of xenobiotics [ethylmorphine and benzo(a)pyrene] by adrenal microsomes increased 3- to 5-fold. Steroid 17 alpha- and(More)
In young (25-day-old) guinea pigs, adrenal and hepatic benzo[a]pyrene (BP) hydroxylase activities were similar but the rates of ethylmorphine (EM) demethylation were greater in adrenals than liver. Between 25 and 50 days of age no sex differences in adrenal or hepatic enzyme activities were demonstrable. The rates of adrenal BP and EM metabolism increased(More)