The enterohepatic recycling of estrogens in cystic fibrosis

It has been suggested that, whereas the 16-alpha glucuronide of estriol is both an enteric mucosal and hepatic metabolite, the 3-glucuronide is predominantly an enteric mucosal metabolite. Thus the latter is only formed when the 16-alpha isomer is secreted in the bile, hydrolysed by the gut flora, reabsorbed and reconjugated. The authors have studied the urinary excretion of both metabolites after the oral administration of a small dose of estriol in order to establish whether their proportions or clearance are changed in cystic fibrosis.