Splanchnic and intestinal uptake and formation of estriol and estriol conjugates in the dog in vivo.
A loading dose of 3H-estriol was given to male dogs followed by a constant infusion. The concentrations of total radioactivity, conjugated estriol metabolites, estriol, estriol-o-glucosiduronate, estriol-16alpha-glucosiduronate, estriol-3-sulfate and estriol-3-sulfate, 16alpha-glucosiduronate were determined in plasma from the femoral artery(A), hepatic vein(HV) and superior mesenteric vein (SMV). From these values the splanchnic (100[1-HV/A]) and intestinal (100[1-SMV/A]) extractions were calculated. The mean splanchnic extraction of total radioactivity was positive (23, SE 3, P less than .01), indicating net uptake by the splanchnic area, possibly due to biliary excretion. The mean splanchnic extraction of estriol was 77, SE 1, P less than .01, also indicating net uptake. The splachnic extractions of estriol-3-glucosiduronate, estriol-16alpha-glucosiduronate and estriol-3-sulfate were negative (-15, SE 3, P less than .01; -23, SE 6, P less than .01; -31, SE 8, P less than .01 respectively) indicating net formation of these conjugates for release into the systemic circulation. The mean intestinal extraction of estriol was 12, SE 4, P less than .01, indicating net uptake by the intestine. This net uptake was associated with mean negative intestinal extractions of estriol-3-glucosiduronate (-15, SE 7, P approximately .05), estriol-3-sulfate (-33, SE 10, P less than .01) and estriol-3-sulfate, 16alpha-glucosiduronate (-53, SE 13, P less than .01), indicating net formation of these conjugates by the intestine.
D000818:Animals; D001659:Biliary Tract / Q000378:metabolism; D004064:Digestive System / Q000378:metabolism*; D004285:Dogs; D004964:Estriol / Q000097:blood / Q000378:metabolism*; D004966:Estrogens, Conjugated (USP) / Q000096:biosynthesis* / Q000097:blood; D005263:Femoral Artery; D005965:Glucuronates / Q000378:metabolism; D006503:Hepatic Veins; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D008642:Mesenteric Veins; D013431:Sulfates / Q000378:metabolism
D004966:Estrogens, Conjugated (USP); D005965:Glucuronates; D013431:Sulfates; D004964:Estriol