Uptake and Metabolism of [1,2-3h]progesterone Injected Intraluminally Into the Uteri of Spayed Mice

Abstract

SUMMARY [1,2-3H]Progesterone (5–50 pg) injected intraluminally into the uterus of spayed mice was retained only to a small extent; producing a 'half-life' of about 30 min compared with > 240 min for [6,7-3H]oestradiol-17β (50 pg). Retention of progesterone by the uterus was not significantly different from that by the plantaris muscle, a non-target tissue. Paper chromatography of extracts indicated that metabolism of [1,2-3H]progesterone occurred in both the uterus and the vagina within 5 min of local injection. There was more metabolism in the vagina and it was qualitatively different. No selective retention of progesterone or its metabolites occurred in either organ. The proportion of the radioactivity present as progesterone over 120 min after injection remained constant.

Oestradiol and Progesterone: Soluble Receptor Levels and Metabolism in the Uterus of the Ovariectomized Ewe

“…In laboratory animals the circulating levels of oestradiol also influence the uterine metabolism of oestradiol and progesterone in vivo and in vitro (Martin and Stone 1965;Pack and Brooks 1970;Armstrong and King 1971;Clark 1973;Saffron et al 1974;Holtermann and Lisboa 1975). In view of this the generally low level of metabolism of these two steroids, particularly to less active compounds, and the lack of influence of steroid treatment, in the present study, is rather surprising.…”

Effects of Oestrogen Priming on the Uptake, Metabolism and Biological Activity of Progestins in the Mouse Uterus

“…Intraluminal injections in 1 µ 0-9 % NaCl solution were made into the ovarian end of one uterine horn with a 10/d Hamilton syringe, through a dorsal incision under Avertin anaesthesia (Clark, 1973). Subcutaneous injections were given in arachis oil.…”

“…Extraction, fractionation and measurement of radioactivity after intraluminal injection Total radioactivity per uterine horn was measured as described previously (Clark, 1973). For identification of metabolites, radioactivity from at least five uterine horns was fractionated by paper chromatography on 0-5 mm silica gel plates (Merck Silica Gel G.F. 254) in méthylène choride: ether (5:2, v/v) at 4°C.…”

“…with little orno metabolism (Martin & Baggett, 1964;Stone & Martin, 1964, 1965Clark, 1973) they show little capacity for the selective retention of progesterone and considerable capacity for its metabolism (Clark, 1973). However the extent to which intra-target organ metabolism plays a role in the action of progesterone remains obscure.…”

The ovarian-uterine vasculature in relation to unilateral endometrial growth in flying foxes (genus Pteropus, suborder Megachiroptera, order Chiroptera)

“…Like Marshall (1953) (Towers and Martin, 1985). If luteal progesterone were sequestered to, and metabolized to inactive compounds by the endometrium, as in rodents (Clark, 1973(Clark, , 1974(Clark, , 1975 (Walsh et ah, 1979) and women (Bendz et ah, 1982b). Recirculation in this way might be a mechanism to regulate follicle growth, ovulation and luteal function (Bendz et ah, 1982a, b).…”