Studies on phenolic steroids in human subjects: <i>IX. Role of the intestine in the conjugation of estriol</i>

N. Inoue; A. A. Sandberg; J. B. Graham; W. R. Slaunwhite

doi:10.1172/JCI105996

Studies on phenolic steroids in human subjects: IX. Role of the intestine in the conjugation of estriol

N. Inoue, A. A. Sandberg, J. B. Graham, and W. R. Slaunwhite Jr.

Published February 1, 1969 - More info

View PDF

Abstract

In order to compare the enteric circulation of estriol-16α-glucosiduronate (see preceding paper) with that of estriol (E₃), 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 (E₃-3Gl,E₃-16Gl) and sulfoglucosiduronate (E₃-3S,16Gl) of estriol. After peripheral injection of E₃, E₃-16Gl was excreted rapidly and E₃-3S,16Gl at a slower and more constant rate. E₃-3Gl was barely detectable after infusion. After injection of E₃ into the portal vein, the excretion of E₃-3S,16Gl was greater and quicker than after peripheral injection. Even in a subject with a complete bile fistula, the urinary excretion of E₃-3S,16Gl was essentially unchanged. Ingestion also produced the same result. Only after instillation into the ileum was a large and rapid excretion of E₃-3Gl obtained, whereas the excretion of E₃-3S,16Gl, and E₃-16Gl were depressed. These results together with those of the preceding paper suggest that E₃ does not readily appear in the small intestine except via a hepatoenteric circulation that produces very little E₃-3Gl. When present in the distal segment of the small intestine, however, absorption, conjugation, and elimination proceed readily.