the following observations suggest that this progesterone originates in the uterus and not in the ovaries : ( 1 ) no active corpora lutea appeared to be present in the ovaries after ovariectomy , ( 2 ) ovariectomized mares showed the same oestrous symptoms in similar experiments and even mating took place , ( 3 ) in the uterine biopsies the concentration of the compound referred to as `` '' 5.4 '' '' , which is assumed to be easily convertible into progesterone , had already increased considerably in the second biopsy , ( 4 ) administration of stilboestrol reduced the rise of the progesterone level in the uterine biopsies as well as in the blood .
C0029939
ovaries
C0029936
ovariectomy