Abstract Reproductive performance is central to profitability in beef cattle operations. Pathogenic stress can result from gram-negative bacteria release of the lipopolysaccharide (LPS) endotoxin which has potential accumulate follicular fluid and impair folliculogenesis steroidogenesis, leading reduced fertility. Elevated LPS concentrations observed acute clinical bacterial infections are reco...

Seasonally breeding animals reproduce during certain times of the year and, subsequently, behaviors, steroid hormone levels, and brain morphology change. The green anole lizard (Anolis carolinensis) is an excellent model to study the regulation of steroid hormone production because they have distinct hormonal and behavioral differences between sexes and seasons. As in other vertebrates, steroid...

In 1950, Frieden and Hisaw (2) described a method for the isolation of relaxin from the ovaries of pregnant sows. This method, which involved extraction of ground whole ovaries with 5 per cent aqueous SaCl, fractionation with ethanol, and finally precipitation with acetone, afforded good yields (200 to 250 GPU’ of relaxin per gm. of fresh tissue), and material of saCsfactory potency (30 to 90 G...

Sex hormones play an active role in inflammatory responses, with androgens being anti-inflammatory, whereas estrogens have both pro- and anti-inflammatory effects. In rheumatoid arthritis (RA) patients, low levels of androgens and high levels of estrone are found in the synovial fluid. Aromatase is the key enzyme for the conversion of androgens into estrogens. Proinflammatory cytokines stimulat...

The suppression of local estrogens levels is of key importance in the treatment of ER-positive breast cancer. Essentially all endocrine strategies act by either suppressing estrogen formation or competitively inhibiting receptor-binding in tumor cells. Nevertheless, little is still known about the local expression of aromatase and sulfotransferase which are the key modulators of intra-tumoral e...

Epidemiological and experimental findings suggest that the development of gastric cancer (GC) is regulated by steroid hormones. In postmenopausal women and older men, the majority of steroid hormones are produced locally in peripheral tissue through the enzymatic conversion of steroid precursors. Therefore, using reverse transcription-quantitative polymerase chain reaction analysis, the mRNA ex...

In recent years, there has been increasing recognition of the importance of steroid aromatization in organs besides the steroidogenic ones. Estrogens formed from C-19 precursors in peripheral tissues can clearly contribute to the levels of estro gens in the circulation, while aromatization in target cells may be an important determinant of the concentration of estrogens to which a particular po...

Previous work has shown that androgens inhibit breast cancer cells and tumor growth. On the other hand, androgens can be converted to mitogenic estrogens by aromatase in breast cancer cells. Here, we report that androgens, such as the aromatizable androstenedione and the non-aromatizable 5alpha-dihydrotestosterone, inhibit MCF-7 cell proliferation. This effect is observed only in the absence or...

BACKGROUND Temporary exposure of follicles to increased levels of androgens may enhance their sensitivity to FSH. The aim of this study was to increase the intraovarian androgen level using aromatase inhibitors and hCG before controlled ovarian stimulation (COH) and to test this concept clinically. METHODS In a prospective, non-randomized study, 45 patients were treated in modified antagonist...

The effects of aromatase inhibitors 4-hydroxyandrostenedione (4-OHA), CGS 16949A, and CGS 20267, and of the antiestrogen tamoxifen (TAM), were studied on the growth of human breast carcinoma in a nude mouse model. To simulate the postmenopausal breast cancer patient, tumors were formed from inoculates of MCF-7 cells transfected with the human aromatase gene to provide a source of non-ovarian es...