The effect of aging on the hydrolysis of cholesterol-7-alpha-H3-oleate by homogenates of chicken aorta.
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Aging↗
Biomedical subjects
G Shyamala
Publications and source records attributed to G Shyamala.
Cholesterol esterification by the mitochondria-rich fraction of the Snell adrenal cortical tumor 494-H and the normal adrenal gland.
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Adrenal Gland Neoplasms↗
In situ localization of progesterone receptors in normal mouse mammary glands: absence of receptors in the connective and adipose stroma and a heterogeneous distribution in the epithelium.
In normal mammary glands of both rodents and humans, progesterone promotes the proliferation of epithelial cells and several lines of evidence suggest that this action of progesterone may be mediated by progesterone receptor (PR). It is well established that normal mammary development involves a complex interplay between the epithelial cells and the surrounding fatty stroma. Furthermore, during mammary development, there is a change in both the relative proportion of epithelial cells and the steady-state levels of PR. Therefore, towards understanding the precise role of PR in mammary development, we have generated a highly sensitive antibody against mouse PR and examined its pattern of localization. Immunoreactive PR was detected only in the epithelial cells of the ducts while both the adipose and fibrous stroma surrounding these ducts were receptor negative. Similarly, PR mRNA was also associated only with the ductal epithelial cells. Approximately only 45-50% of the ductal cells were receptor positive and this distribution remained unchanged whether or not the tissues had been exposed to estrogen, suggesting that they may represent a distinct subpopulation. The potential significance of these findings to mammary development is discussed.
Adipose Tissue↗
An empirical basis for the competition by dexamethasone to progesterone receptors as estimated with the synthetic progestin R5020.
Normal mammary glands of mice contain both progesterone and glucocorticoid receptors and the levels of both these receptors are modulated as a function of development. Measurement of progesterone receptors using the synthetic progestin, R5020, has led to conflicting data both with regard to the presence of progesterone receptor during certain developmental stages of the mammary gland and the ability of the glucocorticoids to compete for specific R5020 binding sites. In this report we have identified experimental conditions which allow for the separate measurements of the progesterone and glucocorticoid receptors in the same cytosol. If sulfhydryl reducing agents such as dithiothreitol are excluded from the assay buffer, R5020 binds to only a single class of high affinity sites in mammary cytosol of virgin mice and these binding sites exhibit a strict steroid specificity characteristic of progesterone receptors. In contrast, if dithiothreitol is included in the buffers, R5020 binds not only to the high affinity sites but also to certain saturable lower affinity sites; these lower affinity sites for R5020 also bind glucocorticoids such as dexamethasone. These findings should facilitate more accurate quantitation of both progesterone and glucocorticoid receptors in normal and neoplastic tissues and also be applicable to studies on the mechanism(s) of progesterone action.
Animals↗