USA Home > Product Directory > Cell Biology > Cell Signaling and Neuroscience > Cytokines, Growth Factors and Hormones > Hormones > Steroid Hormones > Estrogen
Our new Rxi ® -1ms column, designed for GC-MS applications, provides the ultra-low bleed and exceptional inertness needed for analyzing urinary steroid hormones. For this application we derivatized six sex hormones, using methoxylamine HCl and trimethylsilyl imidazole to improve chromatography. Figure 1 shows this variety of derivatized steroid sex hormones, analyzed in less than 25 minutes by using an Rxi ® -1ms column. Note that these compounds elute at temperatures near or above 300°C and that bleed from the Rxi ® -1ms column is negligible at these temperatures. The Rxi ® -1ms column exhibits the inertness needed to produce Gaussian peaks and excellent resolution.
Because steroids are lipophilic, they diffuse easily through the cell membranes, and therefore have a very large distribution volume. In their target tissues, steroids are concentrated by an uptake mechanism which relies on their binding to intracellular proteins (or " receptors ", see below). High concentration of steroids are also found in adipose tissue, although this is not a target for hormone action. In the human male, adipose tissue contains aromatase activity, and seems to be the main source of androgen-derived estrogens found in the circulation. But most of the peripheral metabolism occurs in the liver and to some extent in the kidneys, which are the major sites of hormone inactivation and elimination, or catabolism (see below).