Silastic implants of progesterone produce high circulating levels of both progesterone and 20 alpha-hydroxyprogesterone in ovariectomized, adrenalectomized rats.
Silastic implants of progesterone produce high circulating levels of both progesterone and 20 alpha-hydroxyprogesterone in ovariectomized, adrenalectomized rats.
复制标题
黄体酮的硅橡胶植入物在卵巢切除、肾上腺切除的大鼠中产生高循环水平的黄体酮和20α-羟基黄体酮。
DOI：
10.1095/biolreprod26.3.385
复制
发表时间：
1982
影响因子：
3.6
通讯作者：
Judd,HL
中科院分区：
文献类型：
--
作者：
Lu,JK;Judd,HL
既往研究表明，周期性雌性大鼠中循环的20α-羟孕酮（20α-OH-P）来源于黄体组织中孕酮的酶促转化（Hashimoto和Wiest，1969）。我们最近的发现也揭示了孕酮在卵巢外转化为20α-OH-P的可能性，即在先前假孕的卵巢切除（OVX）大鼠中放置孕酮的硅橡胶植入物不仅产生高血浆孕酮，而且产生20α-OH-P（Gilman等人，1981年）。本研究测定了正常、去肾上腺（ADX）、周期性雌性大鼠及去卵巢、去肾上腺及去卵巢-去肾上腺动物血清20α-羟孕酮（20α-OH-P）和孕酮（P）的含量。在完整的周期性雌性中，20α-OH-P的循环浓度是孕酮的4- 6倍。ADX可使循环中孕酮部分减少，但对20α-OH-P无影响。在OVX和OVX-ADX大鼠中，放置4 cm孕酮硅橡胶植入物可产生高血清孕酮（29 ± 4 ng/ml，平均值± SEM）和20α-OH-P（27 ± 1 ng/ml）浓度。这些发现表明，将孕酮植入雌性大鼠体内可产生高浓度的孕酮和20α-OH-P，并表明卵巢外和肾上腺外系统在持续高循环孕酮条件下可转化为孕酮。通过这个系统，大量的循环孕酮被转化为一种效力较低的促孕化合物，20α-OH-P。
Previous studies indicated that circulating 20α-hydroxyprogesterone (20α-OH-P) in cyclic female rats derived from enzymatic conversion of progesterone in corpus luteum tissue (Hashimoto and Wiest, 1969). A possibility of extraovarian conversion of progesterone to 20α-OH-P also was revealed by our recent finding that placement of Silastic implants of progesterone produced not only high plasma progesterone but also 20α-OH-P in ovariectomized (OVX), previously pseudo-pregnant, rats (Gilman et al., 1981). This study was performed to measure the amounts of serum 20α-OH-P and progesterone in intact or adrenalectomized (ADX), cyclic female rats and in OVX, ADX or OVX-ADX animals with or without progesterone implants.Twenty-four-hour patterns of serum progestins revealed that OVX rats exhibited low progesterone secretion (3–6 ng/ml) and undetectable levels of 20α-OH-P in the absence of ovaries. In intact, cyclic females, circulating concentrations of 20α-OH-P were 4- to 6-fold greater than those or progesterone. ADX resulted in a partial reduction of progesterone but not 20α-OH-P in the circulation. Placement of 4 cm Silastic implants of progesterone produced high serum concentrations of both progesterone (29 ± 4 ng/ml, mean ± SEM) and 20α-OH-P (27 ± 1 ng/ml) in OVX and OVX-ADX rats. These findings demonstrate that placement of progesterone implants into female rats produces high circulating concentrations of both progesterone and 20α-OH-P, and indicate that an extraovarian and extra-adrenal system(s) for progestin conversion is functioning under persistently high circulating progesterone conditions. By this system, large amounts of circulating progesterone are transformed into a less potent progestational compound, 20α-OH-P.