Oestrogen synthesis by the peri-implantation conceptus of the one-humped camel (Camelus dromedarius)

The ability of the embryonic tissues of the dromedary camel (Camelus dromedarius) to synthesize oestrogens in vitro was studied in 15 conceptuses recovered by non-surgical uterine lavage between 10 and 33 days after ovulation. Definitive evidence for strong aromatase activity with synthesis of considerable quantities of oestrogens was obtained at all stages when conceptus tissues were incubated with [3H]androstenedione. A high proportion of the oestrogens was in the form of oestradiol, which contrasts to the higher ratio of oestrone:oestradiol in the oestrogens synthesized by embryonic tissues of horses and pigs. Biopsies of endometrial tissue recovered from pregnant and nonpregnant camels showed great ability to conjugate both oestradiol and oestrone when incubated with tritium-labelled forms of these two hormones.