The Excretion of Steroid Hormone Metabolites in Bile and Feces

Abstract

Publisher Summary This chapter discusses the excretion of steroid hormone metabolites in bile and feces. The presence of steroid hormone activity in bile was first demonstrated nearly fifty years ago. Progress in the analysis of bile is slow compared to that of urine because of the technical problems associated with the qualitative and quantitative analysis of the small amounts of steroids excreted in bile and feces. The availability of labeled steroid hormones greatly facilitated investigations. More recently, the use of gas-liquid chromatography, particularly when associated with mass spectrometry, has facilitated research in this field, and in the last few years a vast amount of data has been accumulated. An understanding of the significance of biliary excretion of steroid hormone metabolites requires some knowledge about the structure of the biliary system and of current ideas on the formation and secretion of bile. The primary units of the biliary system are the bile canaliculi. They are formed as very fine tubules between adjacent pairs of parenchymal cells, each cell contributing one half of the canaliculus. The canaliculi can be seen only by electron microscopy. The membrane of that part of the cell which forms the canaliculus has numerous microvilli which project into the lumen of the canaliculus.