Studies on phenolic steroids in human subjects. IX. Role of the intestine in the conjugation of estriol.
In order to compare the enteric circulation of estriol-16alpha-glucosiduronate (see preceding paper) with that of estriol (E(3)), labeled estriol was administered to six women by several routes: both injection and infusion (300 min) into the cubital vein, injection into the portal vein system, ingestion and instillation into the jejunum and ileum. Urine, collected from 0-2, 2-4, 4-8, 8-12, and 12-24 hr, was analyzed by countercurrent distribution for its content of radioactive 3- and 16-glucosiduronate (E(3)-3Gl,E(3)-16Gl) and sulfoglucosiduronate (E(3)-3S,16Gl) of estriol. After peripheral injection of E(3), E(3)-16Gl was excreted rapidly and E(3)-3S,16Gl at a slower and more constant rate. E(3)-3Gl was barely detectable after infusion. After injection of E(3) into the portal vein, the excretion of E(3)-3S,16Gl was greater and quicker than after peripheral injection. Even in a subject with a complete bile fistula, the urinary excretion of E(3)-3S,16Gl was essentially unchanged. Ingestion also produced the same result. Only after instillation into the ileum was a large and rapid excretion of E(3)-3Gl obtained, whereas the excretion of E(3)-3S,16Gl, and E(3)-16Gl were depressed. These results together with those of the preceding paper suggest that E(3) does not readily appear in the small intestine except via a hepatoenteric circulation that produces very little E(3)-3Gl. When present in the distal segment of the small intestine, however, absorption, conjugation, and elimination proceed readily.
D001658:Biliary Fistula / Q000378:metabolism; D002247:Carbon Isotopes; D002277:Carcinoma / Q000378:metabolism; D003377:Countercurrent Distribution; D004964:Estriol / Q000378:metabolism* / Q000652:urine*; D004966:Estrogens, Conjugated (USP); D005260:Female; D006801:Humans; D007085:Ilium / Q000378:metabolism; D007263:Infusions, Parenteral; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D007421:Intestine, Small / Q000378:metabolism*; D007583:Jejunum / Q000378:metabolism; D014316:Tritium; D014594:Uterine Neoplasms / Q000378:metabolism
D002247:Carbon Isotopes; D004966:Estrogens, Conjugated (USP); D014316:Tritium; D004964:Estriol