不同强度运动对去卵巢大鼠血清雌二醇水平的影响

大鼠雌激素代谢途径及生物学意义研究雌激素作为一种重要的性激素，在大鼠的生长发育、生殖、免疫以及代谢等生理过程中发挥着不可忽视的作用。

而大鼠中雌激素的代谢途径也是研究者们广泛关注的热点话题之一。

本文将从大鼠雌激素代谢途径及其生物学意义两方面进行阐述。

一、大鼠雌激素代谢途径大鼠体内的雌激素主要包括雌二醇（E2）、雌酮（E1）、雌三醇（E3）等。

这些雌激素在体内经历一系列的代谢变化，其中MPA酯化是重要的代谢途径之一。

1. MPA酯化研究发现，在大鼠中MPA（去甲孕酮）是一种重要的代谢物，它可以通过酯化反应稳定存在于大鼠体内。

具体来说，MPA在大鼠肝脏中的儿茶酚-O-甲基转移酶（COMT）以及乙酰转移酶（SULT）的作用下酯化，形成的MPA酯可以通过血液循环输入到病变组织中，从而发挥治疗作用。

2. 细胞色素P450另外，大鼠体内的细胞色素P450代谢途径也是雌激素代谢的重要途径之一。

这些细胞色素P450包括CYP1A1、CYP1A2、CYP1B1等。

研究表明，这些CYP代谢酶除了能够将雌激素代谢为比例较低的E3等物质外，还能够代谢出反式的代谢产物，并形成极具活性的代谢产物4-OHE2。

这种代谢物可以与DNA结合，从而增加DNA突变的风险并诱导肿瘤的发生。

3. 酚类化合物此外，在大鼠中酚类化合物也作为雌激素代谢途径之一，这些化合物包括儿茶素等。

儿茶素可以作为雌激素的最终代谢产物通过分泌到尿液中排出。

二、大鼠雌激素代谢途径的生物学意义大鼠雌激素代谢途径的生物学意义是多方面的。

1. 生育首先，在大鼠的生育过程中，雌激素代谢途径的变化对生育健康起着重要的作用。

雌激素在组织中的浓度以及代谢产物的类型与数量的变化，都能够影响某些生育指标如卵巢发育、输卵管的功能、子宫对胚胎的影响等。

因此，对雌激素代谢途径的研究有助于提高大鼠的生育率。

2. 疾病其次，在很多疾病的发生过程中，雌激素代谢途径的异常都扮演着重要的角色。

比如在乳腺癌的发生过程中，雌激素代谢产物如4-OHE2、16-OHE1等与癌细胞的发生有着密切的关系。

去卵巢大鼠不同时期骨量、骨转换指标、雌激素水平的变化规律及相关性沈耿杨;张顺聪;姚珍松;任辉;江晓兵;梁德;杨志东;唐晶晶;崔健超;林顺鑫;庄洪【摘要】BACKGROUND:There are so many studies about ovariectomized rats at present, but the research on the change rules of bone mass, bone turnover markers, estrogen levels and their correlation in different periods of ovariectomized rats is rarely reported. OBJECTIVE:To analyze the change rules of bone mass, bone turnover markers, estrogen level and their correlation in different periods of ovariectomized rats.&nbsp;METHODS: Thirty-four 3-month-old female Sprague Dawley rats were randomly divided into three groups: baseline group, ovariectomized group and sham operated group. At the beginning of the experiment, the rats in the baseline group were sacrificed, then rats in the ovariectomized group and sham operated group were executed at 4, 8, 12 weeks postoperative respectively. The bone mineral density, bone mass content, area of different zones of the L1-3 lumbar vertebrae and femurs were detected by dual-energy X-ray absorption method, and meanwhile the serum levels of type I procolagen amino-terminal pro-peptide, I colagen carboxy-terminal peptide and estrogen were determined by ELISA. At last, we analyzed the correlation between body mass, bone mineral densityin vitro, type I procolagen amino-terminal pro-peptide, I colagen carboxy-terminal peptide and estrogen levels and the age of ovariectomized rats. RESULTS AND CONCLUSION: (1) The bone mineral density and bone mass contentof the lumbar vertebral and femurs in the ovariectomized group were significantly lower than those in the sham operated group and baseline group at the 4th week after operation (P < 0.05). The bone mineral density and bone mass content in the ovariectomized group were ameliorated obviously at the 8th and 12th weeks compared with those at the 4th week after operation (P < 0.05). The bone mass loss was highest in the L1 and intertrochanteric regions. (2) Serum levels of type I procolagen amino-terminal pro-peptide and I colagen carboxy-terminal peptide in the ovariectomized group were significantly higher than those in the baseline group and sham operated group at the 4th week after operation, but there was no difference at the 8th and 12th weeks. (3) The serum estrogen level in the ovariectomized group was prominently lower than that in the sham operated group and baseline group at the 8th and 12th weeks after operation (P < 0.01 at the 8th week,P < 0.05 at the 12th week). (4) The age was positively correlated with body mass and bone mineral density of the lumbar vertebrae and femursin vitro, while the serum levels of type I procolagen amino-terminal pro-peptide and I colagen carboxy-terminal peptide were negatively correlated with the bone mineral density of the lumbar vertebrae and femurs in vitro (P < 0.01). These results suggested that the bone mass of the lumbar vertebrae and femurs in ovariectomized rats was decreased rapidly firstly, and then rose slowly with time; the bone mass in the L1 and intertrochanteric regions lost seriously; the bone turnover markers showed a significant increase at the beginning of ovariectomy and reduced gradualy to normal condition, while the estrogenlevel was increased at the first month after ovariectomy and then decreased rapidly. In addition, the body mass, bone turnover markers and estrogen level were associated with the change of bone mass.%背景：目前对去卵巢大鼠的研究较多，而对不同时间点大鼠骨量、骨转换指标、雌激素水平的变化规律及各因素的相关性研究报道较少。

不同强度运动对高脂饮食大鼠脂代谢影响本实验旨在探究不同强度的运动对高脂饮食大鼠脂代谢的影响。

为此，我们分别将大鼠分为高脂饮食组和普通饮食组，同时在每组内分别设定低强度运动组、中强度运动组和高强度运动组，共计六个实验组。

我们运用基础代谢率测定、运动负荷测试、体重测定、脂代谢分析等方法对其进行对比和分析。

基础代谢率测定表明，高脂饮食大鼠的基础代谢率显著低于普通饮食大鼠，这是因为高脂饮食会导致胰岛素抵抗和脂代谢紊乱，从而降低基础代谢率。

此外，我们还发现低强度运动组的基础代谢率明显高于其他两组，这是由于低强度运动一般为长时间的有氧训练，可以提高脂肪氧化消耗，从而提高基础代谢率。

运动负荷测试结果显示，不同运动强度的运动对大鼠的张力有着不同的刺激作用。

中强度运动组的运动时间和运动强度均显著高于其他两组，这与人类经常进行的中等强度运动类似。

高强度运动组的运动时间较短，但运动强度高，每次运动对身体的耗能量较大。

低强度运动组的运动时间较长，但运动强度较低，每次运动对身体的消耗较小，但其长期的效果也是显著的。

体重测定结果显示，运动强度越高的组体重下降越快。

此外，我们还发现高脂饮食大鼠的体重明显高于普通饮食大鼠，不过，随着运动时间的延长，高脂饮食大鼠的体重逐渐降低。

这说明，无论是普通饮食还是高脂饮食，运动对于减轻体重都是有着明显的帮助作用的。

脂代谢分析结果显示，不同运动强度的运动对大鼠的脂代谢有不同的影响。

低强度运动组的大鼠脂代谢能力最低，而中强度运动组的大鼠脂代谢能力最高，推测这是由于中强度运动产生的明显的肌肉收缩刺激了肌肉酸激酶（AMPK）的活性，从而通过调节葡萄糖和脂肪代谢途径来提高脂代谢能力的原因。

高强度运动组的脂代谢能力较低，这可能是由于这种运动对身体的消耗较大，身体主要集中在能量供应上，而不是脂代谢方面。

总体来看，长期进行适当运动能够有效改善高脂饮食引起的脂代谢紊乱，进而降低肥胖等代谢性疾病的发生风险，而中强度运动可能是最为理想的运动强度。

跑台运动对去卵巢大鼠肱骨无机矿物质含量的影响卜淑敏杨艺张雪琳王雪净（首都体育学院重点实验室，北京100191）〔摘要〕目的观察中等强度跑台运动对去卵巢大鼠肱骨无机矿物质含量的影响。

方法将60只成年雌性SD大鼠按体重随机分为假手术组、去卵巢静止组和去卵巢运动组，每组20只。

去卵巢运动组每周进行4次时间45min、速度18m/min、跑道倾角5ʎ的跑台训练，持续训练14w。

末次训练24 36h后或停训16w时处死各组一半大鼠，比色法测定血清钙磷水平；1/万天平称量肱骨湿重、去脂肪干重以及煅烧后的灰重。

结果去卵巢16w和32w时，去卵巢静止组肱骨湿重/体重、肱骨去脂肪干重/体重和肱骨灰重/体重均显著低于假手术组（P＜0.05）；血钙水平的差异只在去卵巢16w时显著（P＜0.05），而血磷水平无显著变化。

训练刚结束时，去卵巢运动组肱骨湿重/体重、肱骨去脂肪干重/体重和肱骨灰重/体重显著高于去卵巢静止组（P＜0.05，P＜0.01），但所有差异在停训16w时消失；血钙、血磷水平均无显著变化。

结论中等强度跑台运动能减缓去卵巢大鼠肱骨无机矿物质含量的丢失。

〔关键词〕去卵巢大鼠；骨质疏松；运动；骨矿物质〔中图分类号〕R338〔文献标识码〕A〔文章编号〕1005-9202（2012）01-0063-03；doi：10.3969/j.issn.1005-9202.2012.01.028 Effects of moderate-intensity treadmill exercise on bone mineral content of humerus in ovariectomized ratsBU Shu-Min，YANG-Yi，ZHANG Xue-Lin，et al.Key Laboratory of Capital Institute of Physical Education，Beijing100088，China【Abstract】Objective To observe the effects of moderate-intensity treadmill exercise on bone mineral content of humerus in ovariec-tomized（OVX）rats.Methods Thirty adult female SD rats were randomly divided into following three groups according to their body weight：sham-operation（Sham），OVX static（OVX），and OVX exercised（EX，18m/min，45min/d，5uphill，4times/w）groups.At 14w of the training or16w of the detraining，the serum content of calcium（Ca）and phosphorus（P）were measured by colorimetry.The hu-meral wet weight，the humeral fat-free dry weight，and the humeral ash weight were calculated by sensitive balance.Results At16w or32w after OVX，the serum content of Ca，the ratio of wet weight to body weight，the ratio of fat-free dry weight to body weight and the ratio of ash weight to body weight in OVX group were significantly lower than those of sham group，and the serum Ca content had significant difference between the two groups only at16w，while there was no difference in the serum P content among the three groups.At the end of the training，the ratio of wet weight to body weight，the ratio of fat free dry weight to body weight and the ratio of ash weight to body weight in EX group were significantly higher than those of OVX group.However，all differences disappeared at the end of detraining，and there were no differ-ences in serum Ca and P contents between EX-detraining group and OVX group.Conclusions The moderate-intensity treadmill exercise could mitigate the mineral loss of humerus in OVX rats.【Key words】Ovariectomized rats；Osteoporosis；Exercise；Bone mineral content基金项目：国家自然科学基金资助（30771046）第一作者：卜淑敏（1967-），女，博士，教授，硕士生导师，主要从事运动医学研究。