Free and Conjugated Steroid Estrogen Fractions of Hens’ Urine ,

INTRODUCTION IT HAS been established that the urine of laying hens contains estrone (Ainsworth and Common, 1962), 16-epi-estriol (Hertelendy and Common, 1964) and estradiol-17β (Hertelendy et al., 1965). The presence of estriol and 16, 17-epi-estriol in laying hens’ urine has been demonstrated chromatographically (Mathur and Common, 1967). Studies on the in vivo conversions of injected 14C-labelled estrogens have shown that the hen's urine probably contains also 17-epi-estriol, 16-ketoestradiol, 16-ketoestrone and estradiol-17α (MacRae et al., 1960; Ainsworth et al., 1962, 1964; Hertelendy and Common, 1965; Mulay and Common, 1967). Estrone, estradiol-17β and 16-ketoestrone are quantitatively the most important urinary estrogens of the hen (Ainsworth et al., 1962; Common et al., 1965); there is very considerably less 16-epi-estriol plus 17-epi-estriol than estrone (Mathur et al., 1966). Relatively little is known about the state of combination of hens’ urinary estrogens. Accordingly, we have investigated this matter by injecting 14C-labelled estrone or estradiol-17β into . . .