The effect of cyclic adenosine 3',5'-monophosphate on the uptake of estradiol by the neonatal mouse uterus: an autoradiographic study.

Uterine tissue from neonatal mice was incubated in vitro at 0 degrees C for 1 h in a medium containing 1 X 10(-8) M 3H-estradiol with or without 1 X 10(-4) M dibutyryl cyclic AMP. In some incubations the temperature was raised to 37 degrees C for 15 min after incubation in the cold, in others the temperature was kept at 0 degrees C during this 15 min period. The tissue was frozen in liquid propane cooled in liquid nitrogen, sectioned at 2 or 4 microns, and autoradiograms prepared according to the dry-mount procedure. cAMP increases the cellular uptake of 3H-estradiol in uterine tissue. After rising the temperature to 37 degrees C, grains appeared over the nuclei. cAMP at low temperature increased the cellular uptake of 3H-estradiol, but the grains were not associated with the nuclei. In the autoradiograms the grain number above the epithelium was markedly less than above the stroma.