Takiguchi Shuji, Sugino Norihiro, Esato Kikue, Karube-Harada Ayako, Sakata Aki, Nakamura Yasuhiko, Ishikawa Hitoshi, Kato Hiroshi
Department of Reproductive, Pediatric, and Infectious Science, Yamaguchi University School of Medicine, Yamaguchi 755-8505, Japan.
Biol Reprod. 2004 Feb;70(2):313-8. doi: 10.1095/biolreprod.103.018853. Epub 2003 Oct 1.
Apoptosis contributes to luteal regression in many species. In the postpartum rat, there are two different types of corpora lutea (CL) in the ovary: CL of pregnancy (CLP) and newly formed CL (NCL). To investigate the regulation of apoptosis in the two different types of CL during luteal regression, apoptosis and caspase-3 activity were examined in the CL obtained on Days 7, 15, and 21 of pregnancy and Days 0, 1, 3, 5, 7, and 9 postpartum. Furthermore, the effect of lactation on apoptosis in the CL was examined in two groups of postpartum rats: lactating rats that nurse more than 10 pups, and nonlactating rats that nurse no pups. Apoptotic cells were detected after Day 21 of pregnancy. In the CLP, remarkable increases in the number of apoptotic cells on Days 5 and 9 postpartum were observed in nonlactating rats (P < 0.01), but not in lactating rats. Changes in caspase-3 activity in the CLP were not consistent with those in number of apoptotic cells. In the NCL, an increase in apoptosis was found only on Day 5 postpartum in nonlactating rats (P < 0.01), but not in lactating rats. Changes in caspase-3 activity in the NCL were consistent with those in number of apoptotic cells. In conclusion, apoptosis is, at least in part, involved in luteal regression after parturition, and lactation appears to inhibit apoptosis. This study also suggests the presence of a caspase-3-independent mechanism for apoptosis in CLP regression in the rat.
细胞凋亡在许多物种的黄体退化过程中发挥作用。在产后大鼠的卵巢中，存在两种不同类型的黄体（CL）：妊娠黄体（CLP）和新形成的黄体（NCL）。为了研究黄体退化过程中两种不同类型黄体的细胞凋亡调控机制，我们检测了妊娠第7、15和21天以及产后第0、1、3、5、7和9天获得的黄体中的细胞凋亡情况和半胱天冬酶-3活性。此外，我们还在两组产后大鼠中检测了哺乳对黄体细胞凋亡的影响：一组是哺乳超过10只幼崽的哺乳大鼠，另一组是不哺乳幼崽的非哺乳大鼠。妊娠第21天后可检测到凋亡细胞。在CLP中，非哺乳大鼠在产后第5天和第9天凋亡细胞数量显著增加（P < 0.01），而哺乳大鼠中未观察到这种情况。CLP中半胱天冬酶-3活性的变化与凋亡细胞数量的变化不一致。在NCL中，仅在非哺乳大鼠产后第5天发现凋亡增加（P < 0.01），哺乳大鼠中未出现这种情况。NCL中半胱天冬酶-3活性的变化与凋亡细胞数量的变化一致。总之，细胞凋亡至少在一定程度上参与了产后黄体退化过程，并且哺乳似乎抑制了细胞凋亡。本研究还表明，大鼠CLP退化过程中存在一种不依赖半胱天冬酶-3的细胞凋亡机制。
