PHOTOPERIOD REGULATES TESTIS CELL APOPTOSIS IN DJUNGARIAN HAMSTERS
PHOTOPERIOD REGULATES TESTIS CELL APOPTOSIS IN DJUNGARIAN HAMSTERS
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DOI：
10.1095/biolreprod51.6.1315
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发表时间：
1994-12-01
影响因子：
3.6
通讯作者：
HSUEH, AJW
中科院分区：
文献类型：
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作者：
FURUTA, I;PORKKAHEISKANEN, T;HSUEH, AJW
在Djungarian仓鼠的繁殖活动是由一天的长度的季节性变化控制。暴露于长日照刺激睾丸发育，而暴露于短日照诱导睾丸退化。我们最近发现，大鼠在促性腺激素剥夺后睾丸退化与细胞凋亡的增加有关。在这里，我们试图确定细胞凋亡是否与季节性繁殖的哺乳动物中自然发生的睾丸退化和/或复发有关。将新生雄性仓鼠维持在长日（16 L：8D）直到3周龄，然后转移到短日（8L：16 D）。在暴露于短日照的3天内血清FSH降低后，睾丸重量在第10天降低52%，21天后降低70%。睾丸细胞DNA片段化分析显示，早在转移到短日后5天，低分子量DNA就增加了4.9倍;随后是时间依赖性减少。睾丸细胞凋亡的增加与血清睾酮的降低相关，但间质细胞LH受体含量的降低被延迟。在第二项研究中，将因暴露于短日照3周而睾丸退化的6周龄仓鼠转移回长日照。在光刺激3天内血清FSH增加后，在第5天发现睾丸重量增加2倍。睾丸重量的增加与光刺激5天内睾丸细胞凋亡减少65%有关。此外，血清睾酮和LH受体含量增加后，观察到5和10天的曝光长日，分别。这些数据表明，神经内分泌的变化（包括FSH的释放）诱导不同的光周期长度改变睾丸细胞凋亡，也表明诱导或抑制细胞凋亡在睾丸退化和/或复发中起着重要作用。该仓鼠为研究光周期哺乳动物睾丸细胞凋亡的神经内分泌调控提供了一个有价值的模型。
Reproductive activity in the Djungarian hamster is controlled by seasonal variations in day length. Exposure to long days stimulates testis development, while exposure to short days induces testis regression. We recently found that testis regression after gonadotropin deprivation in rats is associated with increases in apoptosis. Here we sought to determine whether or not apoptosis is associated with the testis regression and/or recrudescence that occurs naturally in seasonally breeding mammals. Newborn male hamsters were maintained on long days (16L:8D) until 3 wk of age before being transferred to short days (8L:16D). Following decreases in serum FSH within 3 days of exposure to short days, testis weight decreased by 52% at Day 10, reaching a 70% decrease after 21 days. Analysis of testis cell DNA fragmentation showed a 4.9-fold increase of low-molecular weight DNA as early as 5 days after transfer to short days; this was followed by a time-dependent decrease. The observed increases in testis cell apoptosis were correlated with decreases in serum testosterone, but decreases in Leydig cell LH receptor content were delayed. In a second study, 6-wk-old hamsters with regressed testes due to a 3-wk exposure to short days were transferred back to long days. After increases in serum FSH within 3 days of photostimulation, a 2-fold elevation in testis weight was found at Day 5. The increase in testis weight was associated with a 65% decrease of testis apoptosis within 5 days of photostimulation. Also, increases in serum testosterone and LH receptor content were observed after 5 and 10 days of exposure to long days, respectively. These data indicate that neuroendocrine changes (including FSH release) induced by varying photoperiod length alter testis cell apoptosis, suggesting also that the induction or inhibition of apoptosis plays an important role in testis regression and/or recrudescence. The Djungarian hamster provides a valuable model for studying the neuroendocrine control of testis apoptosis in,photoperiodic mammals.