Worcester Foundation for Biomedical Research

About: Worcester Foundation for Biomedical Research is a based out in . It is known for research contribution in the topics: Estrone & Estrogen. The organization has 2195 authors who have published 2646 publications receiving 115809 citations. The organization is also known as: Worcester Foundation for Experimental Biology.

Estrogenic Effects of Dehydroepiandrosterone and Its Sulf ate in Rats

Abstract: Administration of DHA (2.5, 5 or 10 mg/day sc) on days 2–5 interfered with pregnancy in rats. This effect could be produced in intact and adrenalectomized rats and was potentiated in partially hepatectomized ones, total failure of implantation being produced by daily doses of 10, 10 and 5 mg, respectively. Although doses of 2.5–10 mg/day of DHA greatly reduced the deciduomal response of the uterus to trauma in pseudopregnant rats, implantation failure was due not to this, but to expulsion of the eggs from the reproductive tract by day 5 of pregnancy. This effect was similar to that produced by administration of estrogens. Cortisol acetate did not influence the effect of DHA on pregnancy. In intact or adrenalectomized immature rats, the uterus responded to administration of DHA with a dose dependent increase in weight and histological changes similar to those produced by estradiol. In ovariectomized and ovariectomized-adrenalectomized animals smaller responses to similar doses of DHA were produced. In inta...

Regulation and Function of Estrogen and Progesterone Receptor Systems

Abstract: We have developed and validated assay methods which are appropriate for studying the subcellular distribution of estrogen receptor (Re) and progesterone receptor (Rp) in hamster uterus during the estrous cycle and pregnancy. Cytosol receptors were monitored by conventional procedures, and nuclear receptors were extracted from nuclei at 2 C using 0.5 M KC1 in buffer containing glycerol and measured by ligand exchange during incubation with [3H] progesterone (P) at 2 C for 24 h or [3H] estradiol-17s (E2) at 30 C for 1 h. The nuclear exchange assay described herein measures total receptor and also permits estimation of unlabeled steroid in the nuclear KC1 extract. Nuclear Rp translocation was shown to be target-tissue specific, hormone specific, and dependent on P dosage under in vivo conditions. The duration of nuclear Rp retention was about 6 h following exogenous P treatment. During the estrous cycle, Re and Rp levels in uterine cytosol and nuclei varied in response to the changing pattern of E2 and P secretion. Our results document a positive relationship between serum E2, nuclear Re and cytosol Rp levels during the follicular phase of the cycle. Nuclear Rp remained low on cycle days 1–3, and increased abruptly on day 4 coincident with preovulatory P secretion and cytosol Rp depletion. Nuclear Rp translocation during the preovulatory period on cycle day 4 was associated with a marked decline in nuclear Re, and the latter was demonstrated to be a rapid (2–4 h) response to P action rather than serum E2 withdrawal. The negative effect of P on nuclear Re levels may represent a fundamental mechanism for P antagonism of E action. Cytosol and nuclear Rp levels in deciduomal and myometrial tissue were responsive to experimental alteration of serum P, indicating that nuclear Rp is maintained by a continuous process of P-induced Rp translocation. Of interest was the finding in pregnant animals that Re levels declined dramatically in deciduoma as compared to myometrium. The loss of cytosol and nuclear Re from deciduomal cells cannot be attributed to changes in serum E2 or P. Thus, the intracellular regulation of Re numbers may change during differentiation of certain target cells such as those found in the deciduoma.

Plasma testosterone and urinary 17-ketosteroids in Japanese and occidentals.

Abstract: Because of racial differences in body hair, a comparison of plasma testosterone and urinary 17-ketosteroids in Japanese and occidental males and females was made. The Japanese women studied had been living either in Japan or in the United States for several years. All the males lived in the United States. There was no difference in the mean values of plasma testosterone of either males or females. No variation was shown in plasma testosterone in ambulatory subjects (6 males and 2 females) in specimens taken at 9 AM and 5 or 9 pm. The 17-ketosteroid excretion of the Japanese males was 6.2±1.0 (sd) mg/m2/24 hr and of the occidental males, 9.4±2.2 (sd) mg/m2/24 hr (p<.001). That of the Japanese females was 5.7±0.5 mg/m2/24 hr and of the occidental females, 7.7±1.9 (sd) mg/m2/24 hr (p<.005).