[Retention of noradrenaline by the rat endometrial epithelium. Action of estradiol]. / Rétention de noradrenaline par l'épithelium d'endomètre de rat. Action de l'oestradiol

The application of the cytochemical fluorescence method on uterine samples obtained from spayed rats, injected with ascorbic acid, oestradiol, norspinephrine and oestradiol plus norepinephrine, permits the visualization of an extraneuronal uptake of norepinephrine by the luminal and glandular epithelium of the rat endometrium. The enhancing of the oestradiol uptake exerted by norepinephrine could be explained in this case by a direct action of norepinephrine on the target cell.

[Competition between estradiol and various progestogens at the level of the rat hypothalamus]. / Compétition entre l'oestradiol et différents progestagènes au niveau de l'hypothalamus du rat

PIP: Short-term cultures (32 hours) of rat hypothalamus were incubated with tritiated estradiol and either medroxyprogesterone, Ro 4-8347, norgestrel, or lynestrenol to find out whether the progestagens would compete for estrogen receptors. Each culture was preincubated for 8 hours in medium 199, washed, incubated for 16 hours with progestagen (preincubation experiment), and incubated a further 8 hours with labeled estrogen (control or preincubation experiment) or estrogen and the progestagen (simultaneous experiment). Ro 4-8347 (1,6-dehydro-6-chlororetroprogesterone) .6 ng/ml inhibited estradiol uptake when it was added before the estrogen. Lynestrenol and norgestrel displaced estradiol in simultaneous cultures only. Medroxyprogesterone reduced estradiol uptake when it was added both before and during the estradiol incubation.^ieng