| Abstract: | On specified days of the estrus cycle, pregnancy, pseudopregnancy, or following administration of estradiol-17 beta, progesterone, or both, nulliparous, ovariectomized rats were assigned to 1 of 3 treatment groups. Group 1 received nialamide and norepinephrine 5 hours and 15 minutes, respectively, before killing. Group 2 received nialamide alone 5 hours before killing. Group 3 received L-dihydroxyphenylalanine 2 hours before killing. Pregnant, pseudopregnant, and progesterone-treated rats from Group 1 showed a greenish-yellow fluorescence in uterine subepithelial cells. Groups 2 and 3 did not show this fluorescence. It was suggested that this fluorescence was due to the extraneuronal uptake of norepinephrine, and that progesterone is necessary for the uptake of norepinephrine by subepithelial cells since no florescence was observed in the rat estrus cycle but ovariectomized rats treated with progesterone showed florescence. |
