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W Rosner

Publications and source records attributed to W Rosner.

100 records · Page 6Linked to original sources
PubMed1968

Testosterone-binding globulins in human plasma: studies on sex distribution and specificity.

When human plasma is mixed with testosterone-(3)H and subjected to electrophoresis on paper in glycine acetate buffer at pH 8.6, at least two proteins other than albumin bind the testosterone. In normal women 80.5 +/- 1.9% (SEM) of the recovered radioactivity migrates with the beta-globulins, 7.3 +/- 0.80% with the inter-alpha-globulins, and 4.3 +/- 0.40% with albumin. In normal men the percentages are 69.3 +/- 3.0%, 14.3 +/- 1.6%, and 6.2 +/- 1.1%, respectively. These differences between men and women in binding among the beta-globulins and inter-alpha-globulins are statistically significant (P < 0.001). The highest percentages of radioactivity associated with the beta-globulins are seen in infants of both sexes, men receiving diethylstillbestrol, and pregnant women. These same subjects have the lowest percentages of radioactivity associated with the inter-alpha-globulins. Experiments with carrier testosterone indicate that at least some of the differences between the normal men and women and infants can be explained by differences in the concentration of endogenous testosterone. This factor alone, however, cannot explain the increased binding among the beta-globulins in the men receiving diethylstilbestrol or in the pregnant females. In this system estrone, estradiol, dehydroisoandrosterone, androsterone, 17alpha-hydroxyprogesterone, and 19-nortestosterone compete with testosterone for binding sites on the proteins. None is as potent as testosterone itself.

Alpha-Globulins↗
PubMedDate not supplied

Androgen and estrogen signaling at the cell membrane via G-proteins and cyclic adenosine monophosphate.

Androgens and estrogens are well-known to initiate their actions by binding to specific intracellular receptors. The steroid-receptor interaction, the receptors, and the details of transcriptional activation consequent to the binding of these steroids with their respective receptors have been, and continue to be, intensively studied. More recently, it has become increasingly apparent that steroids may interact with cells by other than this classic pathway. This communication will deal with activation by sex hormones of a signal transduction pathway that originates at the cell membrane and utilizes cyclic adenosine monophosphate (cAMP) as a second messenger. The system consists of three components, an agonist steroid, sex hormone-binding globulin (SHBG), and a membrane receptor (R(SHBG)) for SHBG. SHBG is a well-characterized plasma protein that has two binding sites, one binds certain estrogens and androgens, and the other binds to R(SHBG). The characteristics of this novel signal transduction system, from the interaction of SHBG with R(SHBG), to the intermediacy of G-proteins, to cAMP generation, to downstream effects of the second messenger will be reviewed.

Androgens↗
PubMedDate not supplied

Sex hormone-binding globulin mediates steroid hormone signal transduction at the plasma membrane.

Sex hormone-binding globulin is a plasma glycoprotein that binds certain estrogens and androgens with high affinity. Over the past several years it has been shown that, in addition to functioning as a regulator of the free concentration of a number of steroid hormones, SHBG plays a central role in permitting certain steroid hormones to act without entering the cell. The system is complex. SHBG interacts with a specific, high affinity receptor (R(SHBG)) on cell membranes that appears to transduce its signal via a G protein. The SHBG-R(SHBG) complex causes the activation of adenylyl cyclase and the generation of cAMP within a matter of minutes after exposure to an appropriate steroid. Only steroids that bind to SHBG can activate SHBG-R(SHBG), but not all steroids that bind have this function, e.g. are agonists. All steroids that bind to SHBG but do not activate adenylyl cyclase are antagonists. The signals generated by the steroid-SHBG-R(SHBG) complex generate messages that have effects on the transcriptional activity of classic, intracellular receptors for steroid hormones. These and other downstream effects of this system are reviewed.

Cell Membrane↗