The Basilica Julia

Inhibition by α‐amanitin of the oestradiol‐induced increase in α‐amanitin insensitive RNA polymerase in immature rat uterus

“…The activity of low salt DNA-dependent RNA polymerase in the rat uterus rises rapidly after in vivo treatment wtih oestradiol( [2] , see figures : zero time ordinates). The oestradiol-stimulated increase in RNA synthesis in uterus nuclei prepared immediately after decapitation decreases significantly if the uteri have previously been incubated in Eagle's medium.…”

“…Following incubation, the uteri were homogenized. A nuclear preparation was obtained and the RNA polymerase assayed [2]. The nuclear suspension from the uteri of each group was divided equally for 2-5 determinations.…”

“…The injection of oestradiol to the prepuberal or castrated rat results, 2-3 hr later, in a large increase in RNA biosynthesis [l] and in an increased ability of uterine nuclei to incorporate nucleoside triphosphates into RNA [2]. Various reports have established that oestrogen-stimulated RNA is largely of ribosomal nature [3,4] .…”

Receptor Transformation in Estrogen Action

“…Indirect evidence suggests that production of messenger RNA for a specific soluble protein in the rat uterus is an especially early event (DeAngelo Sc Gorski 1970, Baulieu et al 1972. It was found that the RNA polymerase activity of nuclei isolated from uteri of immature or castrate rats is increased two-to three-fold by administration of estradiol to the animal one to four hours before the uteri are excised (Gorski 1964, Nicolette et al 1968, Raynaud-Jammet et al 1971, Barry Se Gorski 1971. This effect on RNA polymerase appears to be qualitative as well as quantitative-, nearest neighbor frequency analysis shows that the RNA synthesized by uterine nuclei isolated from estrogen-treated animals contains a higher content of cytidine and guanosine linkages as compared to adenosine and uridine (Barton and Liao 1967, Trachewsky Se Segal 1967, Nicolette Se Babler 1972.…”