Gregoraszczuk E L
Laboratory of Reproductive Physiology and Toxicology, Department of Physiology, Institute of Zoology, Jagiellonian University, Kraków, Poland.
Endocr Regul. 2000 Sep;34(3):151-5.
To examine whether the action of triiodothyronine on aromatase activity in porcine follicular cells is related to the modulation of estradiol receptor.
Medium and large preovulatory follicles were incubated in Parker medium (M199) supplemented with 5 % of calf serum as a control medium or with addition of triiodothyronine (T3; 10 -9 M), tamoxifen (TMX; 0.1 mM ) or T3+TMX. The media were collected after 48 h, and assayed for progesterone (P4) and estradiol (E2) secretion by RIA.
T3 added to the medium decreased E2 secretion by both medium and large preovulatory follicles (119.7 % and 123.8 %, respectively; P<0.05). In contrast, T3 increased the secretion of P4 by medium (136 %; P<0. 05), while decreased the P4 secretion by large preovulatory follicles (123 %; P<0.05). The effect of TMX added alone was also dependent on follicular development. Estradiol secretion by medium follicles was 2.5 fold higher (p<0.01) than in control and 2.9 fold higher (P<0.01) than in T3 treated cells. In preovulatory follicles basal E2 secretion was not affected by TMX, while 1.2 fold higher (P<0.05) secretion compared to T3 treated cells was noted. On the other hand, TMX suppressed basal P4 secretion in medium and preovulatory follicles 1.5 fold (P<0.01) and 1.3 fold (P<0.05), respectively. The same phenomenon was observed in T3 treated cells. TMX added to the culture media decreased P4 secretion by medium follicles 1.8 fold (P<0.01) and that by preovulatory follicles 1.3 fold (P<0.05).
The reversed T3 action on estradiol secretion by both medium (P<0.05) and large preovulatory (P<0.01) follicles in TMX treated follicles suggests the up-regulation of ER by triidothyronine.
研究三碘甲状腺原氨酸对猪卵泡细胞芳香化酶活性的作用是否与雌二醇受体的调节有关。
将中、大型排卵前卵泡在添加5%小牛血清的帕克培养基（M199）中培养作为对照培养基，或添加三碘甲状腺原氨酸（T3；10 -9 M）、他莫昔芬（TMX；0.1 mM）或T3+TMX。48小时后收集培养基，用放射免疫分析法测定孕酮（P4）和雌二醇（E2）的分泌。
添加到培养基中的T3降低了中、大型排卵前卵泡的E2分泌（分别降低了119.7%和123.8%；P<0.05）。相反，T3增加了中型卵泡的P4分泌（增加了136%；P<0.05），而降低了大型排卵前卵泡的P4分泌（降低了123%；P<0.05）。单独添加TMX的作用也取决于卵泡的发育。中型卵泡的雌二醇分泌比对照高2.5倍（P<0.01），比T3处理的细胞高2.9倍（P<0.01）。在排卵前卵泡中，基础E2分泌不受TMX影响，但与T3处理的细胞相比，分泌高1.2倍（P<0.05）。另一方面，TMX分别抑制中型和排卵前卵泡的基础P4分泌1.5倍（P<0.01）和l.3倍（P<0.05）。在T3处理的细胞中也观察到相同现象。添加到培养基中的TMX使中型卵泡的P4分泌降低1.8倍（P<0.01），使排卵前卵泡的P4分泌降低1.3倍（P<0.05）。
在TMX处理的卵泡中，T3对中型（P<0.05）和大型排卵前（P<0.01）卵泡雌二醇分泌的相反作用表明三碘甲状腺原氨酸上调了雌激素受体。
