The uptake of norepinephrine by rat uterine subepithelial cells under normal and experimental conditions

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.     

Site of inhibition by 2-amino-1,1,3-tricyanopropene of photosynthetic oxygen evolution by spinach leaf chloroplasts (Short Communication)

2-Amino-1,1,3-tricyanopropene inhibits photosynthetic O₂ evolution, but, unlike 3-(3,4-dichlorophenyl)-1,1-dimethylurea, has little effect on the steady-state fluorescence of chlorophyll. In chloroplasts prepared from spinach leaves and inhibited by 2-amino-1,1,3-tricyanopropene, a 3-(3,4-dichlorophenyl)-1,1-dimethylurea-sensitive photoreduction of ferricyanide may be restored by addition of semicarbazide. It is concluded that 2-amino-1,1,3-tricyanopropene acts at a point close to the photo-oxidation of water.