Metabolism of sodium oestrone ( 35 S)sulphate in the rat

Intraperitoneal, intravenous or oral administration of sodium oestrone [(35)S]-sulphate to male and female Medical Research Council hooded rats is followed by the rapid excretion of the bulk of the radioactivity in urine in the form of inorganic [(35)S]sulphate. Pre-treatment of rats with an antibiotic regimen does not affect the results except in the case of oral administration, when relatively large amounts of the dose are recovered as ester [(35)S]sulphate in faeces. Intravenous administration of the labelled ester to male and female rats with cannulae in bile duct and ureter gave results similar to those obtained with free-range animals. Only small amounts of radioactivity appeared in bile and this was mainly in the form of ester sulphate, including both oestrone [(35)S]sulphate and oestradiol-17beta 3[(35)S]-sulphate. Whole-body radioautography pinpointed the liver as the probable site of the desulphation of the sulphate ester and this was confirmed by liver and kidney perfusion experiments and by studies with rats in which kidney function had been eliminated by ligation of the renal pedicles.