低聚异麦芽糖对模拟失重大鼠肠道益生菌以及钙代谢和骨矿盐密度影响的初步研究

目的：研究低聚异麦芽糖对模拟失重大鼠肠道益生菌的影响以及与骨钙代谢变化的关系。方法：30只雄性SD大鼠随机分为3组（每组10只）FC组;普通对照组（饲喂普通饲料）;SC组,模拟失重对照组（饲喂普通饲料）;SS组,模拟失重低聚异麦芽糖组（饲喂普通饲料 低聚异麦芽糖）,实验期21d。结果：SC组大鼠肠道益生菌（主要是双歧杆菌和乳杆菌）数量、饲料钙的表观吸收率、股骨骨密度（BMD）,骨钙含量以及骨钙素（BGP）的水平显著低于FC组,而血钙水平明显高于FC组;SS组大鼠肠道益生菌数量,饲料钙的表观吸收率,骨密度,骨钙含量以及骨钙素水平较SC组高,血钙水平显著低于SC组。结论：低聚异麦芽糖可以促进模拟失重大鼠肠道益生菌的增殖,减少股骨骨质的丢失,提高股骨BMD,增加骨形成,对骨代谢产生一定的有益影响。     

低聚木糖对模拟失重大鼠肠道微生态的影响

目的 研究低聚木糖对模拟失重大鼠肠道微生态的影响。方法 采用大鼠尾部悬吊法模拟失重。32只雄性SD大鼠随机分为4组,每组8只：FC组（地面对照组,饲喂基础饲料）,FS组（地面处理组,饲喂添加低聚木糖的饲料）,SC组（尾吊对照组,饲喂基础饲料）。SS组（尾吊处理组,饲喂添加低聚木糖的饲料）,实验21d,SC和SS组解除尾吊继续观察。实验21d。采用选择性培养基对大鼠粪便肠杆菌、肠球菌、类杆菌、双歧杆菌以及乳杆菌进行定量测定。结果 SC组与FC组相比,双歧杆菌数量减少,肠杆菌和肠球菌数量增加;FS组比FC组双歧杆菌数量增加显著,肠杆菌和肠球菌有不同程度的减少,SS组比SC组双歧杆菌数量增加显著,肠杆菌和肠球菌也有不同程度的减少。类杆菌和乳杆菌变化不明显。尾吊解除期,SS组双歧杆菌数量比SC组更快恢复到正常水平。结论 低聚木糖可促进尾吊大鼠肠道益生菌主要是双歧杆菌的增殖,一定程度上促进由于模拟失重造成肠道微生态失调的平衡,并对条件致病菌具有一定的抑制作用。     

施普瑞螺旋藻对尾吊模拟失重大鼠肠道微生态失调的调整作用研究

目的：研究模拟失重条件下,施普瑞螺旋藻对大鼠肠道微生态失调的调整作用。方法：将基础饲料中加入5%的螺旋藻作为处理组饲喂大鼠,用选择性培养基分别对肠球菌、肠杆菌、类杆菌、乳杆菌以及双歧杆菌定量测定,扫描电镜观察大鼠盲肠上皮细胞的组织变化,结果：螺旋藻处理组过路菌群中肠杆菌和肠球菌数量变化并不明显;原籍菌群中双歧杆菌较对照组显著增多,类杆菌和乳杆菌的数量差异没有显著性,模拟失重条件下SD大鼠盲肠上皮有肿胀细胞出现,并且肠道上皮绒毛排列紊乱、稀疏、而螺旋藻处理组中只发现有少量的肿胀细胞,上皮绒毛致密,排列较整齐。结论：旋普瑞螺旋藻具有纠正在模拟失重条件下大鼠肠道微生态平衡失调的作用。     

模拟失重对大鼠肠道菌群影响的研究

目的：研究模拟失重条件下大鼠肠道菌群变化情况。方法：选择性培养基分别对肠球菌、肠杆菌、类杆菌、乳杆菌以及双歧杆菌进行定量测定,扫描电镜观察大鼠盲肠上皮细胞的组织变化。结果：过路菌群中肠杆菌和肠球菌数量增加显著;原籍菌群中双歧杆菌减少十分明显,乳杆菌的数量也有不同程度的减少,而类杆菌的数量有增加的趋势。SD大鼠盲肠出现了肿胀细胞,上皮细胞颈毛排列紊乱、稀疏。结论：模拟失重条件下大鼠肠道微生态出现平衡失调。     

氨基酸螯合钙增加骨密度作用的实验研究

为探讨氨基酸螯合钙的增加骨密度作用,实验设低、中、高三个剂量组,另设一个低钙对照组和一个碳酸钙对照组,以200、400、1200mg/kg·bw(相当于人体推荐剂量5、10、30倍)剂量的氨基酸螯合钙给大鼠灌胃13wk,饮用去离子水和摄食低钙饲料,测定大鼠身长、股骨重量、股骨钙含量及骨密度钙表观吸收率等相关指标.结果实...     

肠道菌群及内毒素在多器官功能不全综合征时的变化

目的　探讨肠道菌群及内毒素在多器官功能不全综合征( MODS)时的变化。方法　取SD大鼠,腹腔注射无菌酵母多糖A制备MODS模型,检测大鼠肠道菌群、外周血和门静脉血中的内毒素以及肠道游离内毒素含量,并进行定量分析。结果　模型组大鼠肠道专性厌氧菌的数量明显减少,革兰阴性杆菌和双歧杆菌的比例倒置,内毒素含量明显增加,与对照组比差异有显著性( P<0 .0 5 )。结论　MODS时肠道细菌微生态发生明显改变,肠道内毒素池与肠道革兰阴性杆菌的变化密切相关     

大气污染对大鼠呼吸道微生态的影响研究

探讨了大气污染引起呼吸道症状和机体健康效应的作用机理,为防治大气污染及其对机体的损害提供理论依据。采用模拟现实大气污染的方法,分高、中、低浓度用Wistar大鼠制备大气污染动物模型,对大鼠口咽部菌群进行定性、定量、定位检测,动态研究。大气污染大鼠模型口咽部微生态发生改变。与污染前比,肺炎克雷伯杆菌等致病菌检出率明显增加(P<0.05),厌氧菌含量明显减少(P<0.05),并且随着染毒时间厌氧菌和细菌总量都呈明显下降趋势(P<0.05);口咽部菌群含量在一定范围内波动,没有随着染毒浓度改变而呈明显改变。大气污染对呼吸道正常菌群有毒害作用,对微环境有破坏作用,导致微环境改变,正常菌群含量减少,致病菌定植,是呼吸道疾病发病率升高的重要因素之一。     

被动吸烟对大鼠口咽部微生态的影响

目的探讨被动吸烟对呼吸道微生态的影响的机制,为预防吸烟对机体健康的损害提供理论依据。方法采用模拟被动吸烟的方法,对健康Wistar大鼠进行大气污染,研究大鼠口咽部菌群污染前后的变化。结果被动吸烟前后大鼠口咽部的微生态菌群明显发生改变（P〈0.5）。吸烟前与吸烟后相比致病菌如金黄色葡萄球菌、肺炎克雷伯菌等检出率明显增高（P〈0.5）,厌氧菌密度减少,随着被动吸烟时间的延长,细菌的密度呈上下波动,且厌氧菌菌群密度变化更为明显（P〈0.5）。结论被动吸烟对大鼠口咽部有破坏作用,导致菌群发生改变,致病菌增多,是呼吸道疾病发病率升高的重要因素之一。     

甲壳低聚糖的微生态学效应

目的 :了解甲壳低聚糖的微生态学效应 ,为其开发为微生态调节剂提供实验依据。方法 :用甲壳低聚糖〔6 0 0 m g/ (kg· d)〕给正常小鼠、肠道脱污染模型小鼠及 STZ糖尿病模型小鼠连续灌胃 7d及 2 1d,用添加 0 .3%甲壳低聚糖的高脂饲料为高血脂症大鼠模型连续灌胃 4 2 d。各空白对照组均用等体积无菌盐水灌胃。而后分析各组动物肠菌群 ,并测定 STZ糖尿病小鼠血糖、高血脂症大鼠 TC及 HDL- C值。结果 :甲壳低聚糖可以优化正常小鼠肠菌群 ,双歧杆菌数较空白对照组明显增多 (P<0 .0 5 ) ,B/ E值为对照组19.3倍 ,可纠正实验动物因肠道脱污染、糖尿病及高血脂症所致的肠菌群失调 ,双歧杆菌或乳杆菌相应增加 ,与相应空白对照组比较 ,其差异均有显著性意义 ,可以明显降低糖尿病小鼠血糖及高血脂症大鼠血清TC值。结论 :甲壳低聚糖具有良好的微生态学效应 ,可作为微生态调节剂开发应用     

野外训练坦克兵肠道菌群的微生态学研究

目的：观察坦克兵野外训练的极端环境条件对坦克乘员肠道菌群的影响。方法：通过活菌定量培养计数法,动态观察32例参训坦克乘员粪便中肠菌群的变化规律。结果：参训后与参训前及对照组比较,肠道菌群中双歧杆菌、乳酸杆菌、类杆菌的数量均非常显著性降低(P＜0．001);而肠杆菌和肠球菌数量均非常显著性升高(P＜0．001);B/E值非常显著性降低(P＜0．001);梭杆菌数量非常显著性升高(P＜0．001);组间各厌氧菌种植出阳性率差异无显著性(X2检验,P＞0．05)。结论：坦克兵野外训练的极端环境条件对参训坦克乘员肠道菌群的生长、繁殖产生显著的负面影响,可打破肠道微生态平衡,但其肠道内厌氧菌群中各菌种的定植确有一定的稳定性。     

The effect of dehydroepiandrosterone administration on intestinal calcium absorption in ovariectomized female rats

[Purpose] Dehydroepiandrosterone (DHEA) administration reportedly recovers osteoporosis, a bone disorder associated with bone deficiency in postmenopausal women. However, the physiological mechanism of DHEA in osteoporosis remains elusive, especially in terms of intestinal calcium absorption. Therefore, we investigated the effect of DHEA administration on calcium absorption in ovariectomized (OVX) female rats using an estrogen receptor antagonist.[Methods] Female Sprague-Dawley rats (n=23, 6 weeks old) were randomized into three groups: OVX control group (OC, n=7), OVX with DHEA treatment group (OD, n=8), and OVX with DHEA inhibitor group (ODI, n=8) for 8 weeks.[Results] Intestinal calcium accumulation, as well as the rate of absorption, demonstrated no significant differences during the experimental period among investigated groups. The bone mineral density (BMD) of the tibia at the proximal metaphysis was higher in the OD group than that in the OC group (p<0.05); however, BMD of the ODI group showed no significant difference from investigated groups. Furthermore, the BMD of the tibia at the diaphysis did not significantly differ among these groups.[Conclusion] We revealed that DHEA administration does not involve intestinal Ca absorption, although this treatment improves BMD levels in OVX rats. These observations indicate that the effect of DHEA on the bone in postmenopausal women is solely due to its influence on bone metabolism and not intestinal calcium absorption.     

Effect of oophorectomy on expression of calcium sensing receptor mRNA in rat duodenal mucosa

Calcium sensing receptor (CaR) in duodenal mucosa may be involved in active calcium absorption. Estrogen deficiency results in decreased intestinal calcium absorption. Effects of bilateral oophorectomy (OVX) have been studied on calcium homeostasis, bone mineral density (BMD) and CaR mRNA levels in duodenal mucosa at 4 weeks in adult female Sprague Dawley rats and compared with those in sham-operated and control group. There was no significant change in serum corrected calcium, inorganic phosphorous, calcidiol and intact parathyroid hormone in all the three groups. OVX rats had a significant decline in serum estrogen (E2) levels and alkaline phosphatase. They also had a significant decrease in BMD (DXA) at lumbar spine in vivo, and proximal and distal tibia in vitro while there was no significant change in serum E2 and BMD parameters in sham-operated and control rats. Northern blot analysis revealed no significant change in the CaR mRNA expression in duodenal mucosa in all three groups. The results suggests that CaR mRNA expression in duodenal mucosa is not affected by physiological circulating concentrations of estradiol in rats.     

Improving effect of feeding with a phosphorylated guar gum hydrolysate on calcium absorption impaired by ovariectomy in rats

We have previously reported that a phosphorylated guar gum hydrolysate (P-GGH) promoted calcium absorption and the accumulation of bone calcium in rats. We now investigate the effect of P-GGH (50 g/kg of diet) on the intestinal calcium absorption and bones of ovariectomized (OVX) rats in comparison with sham-operated rats over a six-week ingestion period. The apparent calcium absorption was decreased by aging and ovariectomy in the rats fed on the control and GGH diets (50 g/kg of diet), but not in the rats fed on the P-GGH diet. The absorption was higher in the P-GGH group than in the GGH and control diet groups in the fourth and sixth weeks after feeding the test diets to OVX rats. Femoral calcium and strength were decreased by OVX in the rats fed on the control and GGH diets, but not in the rats fed on the P-GGH diet. The values of these parameters were higher in the P-GGH group than in either the control or GGH group of OVX rats. The amount of soluble calcium in the ileal contents was higher in the P-GGH group than in the control and GGH groups. These results indicate that P-GGH may be useful for preventing the reduction of intestinal calcium absorption and bone in the condition of estrogen deficiency.     

Effect of shellfish calcium on the apparent absorption of calcium and bone metabolism in ovariectomized rats

Fossil shellfish powder (FS) and Ezo giant scallop shell powder (EG) were rendered soluble with lactate and citrate under decompression (FSEx and EGEx, respectively) and we examined the effects of lactate-citrate solubilization of FS and EG on mineral absorption, tissue mineral contents, serum biochemical indices and bone mineral density (BMD) in ovariectomized (OVX) rats. The apparent absorption ratios of minerals tended to be high in the rats fed with the solubilized mineral sources, those in the FSEx group being significantly higher than in the FS group. There was no significant difference in the tibia mineral content among the OVX groups. BMD at the distal femoral diaphysis was significantly increased by FSEx and EGEx feeding. It is suggested that solubilization with lactate and citrate under decompression increased the solubility and bioavailability of calcium from such natural sources of shellfish calcium as FS and EG.     

Effects of vitamin K2 administration on calcium balance and bone mass in young rats fed normal or low calcium diet

OBJECTIVE: The purpose of this study was to examine the effects of vitamin K2 administration on calcium balance and bone mass in young rats fed a normal or low calcium diet. METHODS: Forty female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into four groups with 10 rats in each group: 0.5% (normal) calcium diet, 0.1% (low) calcium diet, 0.5% calcium diet + vitamin K2 (menatetrenone, 30 mg/100 g chow diet), and 0.1% calcium diet + vitamin K2. After 10 weeks of feeding, serum calcium and calciotropic hormone levels were measured, and intestinal calcium absorption and renal calcium reabsorption were evaluated. Bone histomorphometric analyses were performed on cortical bone of the tibial shaft and cancellous bone of the proximal tibia. RESULTS: Feeding a low calcium diet induced hypocalcemia, increased serum parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D [1,25(OH)2D] levels with decreased serum 25-hydrovyvitamin D [25(OH)D] level, stimulated intestinal calcium absorption and renal calcium reabsorption, and reduced cortical bone mass as a result of decreased periosteal bone gain and enlarged marrow cavity, but did not significantly influence cancellous bone mass. Vitamin K2 administration in rats fed a low calcium diet stimulated renal calcium reabsorption, retarded the abnormal elevation of serum PTH level, increased cancellous bone mass, and retarded cortical bone loss, while vitamin K2 administration in rats fed a normal calcium diet stimulated intestinal calcium absorption by increasing serum 1,25(OH)2D level, and increased cortical bone mass. CONCLUSION: This study clearly shows the differential response of calcium balance and bone mass to vitamin K2 administration in rats fed a normal or low calcium diet.     

Effects of vitamin D supplementation on calcium balance and bone growth in young rats fed normal or low calcium diet

OBJECTIVE: We examined the effect of vitamin D supplementation on bone growth in young rats fed a normal or low calcium diet. METHODS: Fifty female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into five groups with 10 rats in each group: baseline control, 0.5% (normal) or 0.1% (low) calcium diet, and 0.5 or 0.1% calcium diet + vitamin D (25 microg/100 g, food intake). Duration of the experiment was 10 weeks. RESULTS: Vitamin D supplementation stimulated intestinal calcium absorption and increased urinary calcium excretion in rats fed a low or normal calcium diet. Vitamin D supplementation prevented the reduction in periosteal bone gain but enhanced enlargement of the marrow cavity and reduced the maturation-related cancellous bone gain in rats fed a low calcium diet, and increased the maturation-related cancellous and cortical bone gains in rats fed a normal calcium diet. CONCLUSION: This study shows the differential effects of vitamin D supplementation on born growth in young rats fed a normal or low calcium diet.     

海藻酸钙对骨质疏松症大鼠骨骼肌SDF-1含量和骨密度的影响

摘要 目的：探讨海藻酸钙对骨质疏松症大鼠骨骼肌基质细胞衍生因子-1（Stromal Cell-derived Factor-1,SDF-1）含量和骨密度的影响。方法：骨质疏松症大鼠（n=48）随机平分为三组-模型组、尼尔雌醇组与海藻酸钙组,在建模后1周后三组分别给予双蒸水、0.1 mg/100 g尼尔雌醇与37.5 mg/mL海藻酸钙/枸杞多糖凝胶微球水溶液灌胃治疗,1 次/d,检测大鼠骨骼肌SDF-1含量和骨密度变化情况。结果：（1）尼尔雌醇组与海藻酸钙组给药第4周与第8周的血清钙离子含量高于模型组（P<0.05）,磷离子含量低于模型组（P<0.05）,尼尔雌醇组与海藻酸钙组对比差异有统计学意义（P<0.05）;（2）尼尔雌醇组与海藻酸钙组给药第4周与第8周的骨骼肌SDF-1含量低于模型组（P<0.05）,海藻酸钙组低于尼尔雌醇组（P<0.05）;（3）尼尔雌醇组与海藻酸钙组给药第4周与第8周的腰椎和股骨骨密度高于模型组（P<0.05）,海藻酸钙组低于尼尔雌醇组（P<0.05）;（4）尼尔雌醇组与海藻酸钙组给药第4周与第8周的股骨最大载荷、最大应力高于模型组(P<0.05),海藻酸钙组高于尼尔雌醇组（P<0.05）;（5）海藻酸钙组造血细胞数量较多,骨皮质结构较完整,致密均匀粗壮,小梁数目明显增多,骨髓腔变小。结论：海藻酸钙在骨质疏松症大鼠的应用能抑制骨骼肌SDF-1的释放,有助于提高骨密度,改善骨生物力学指标,提高血清钙离子含量,降低磷离子含量。     

Magnesium Supplementation through Seaweed Calcium Extract Rather than Synthetic Magnesium Oxide Improves Femur Bone Mineral Density and Strength in Ovariectomized Rats

Commercially available seaweed calcium extract can supply high amounts of calcium as well as significant amounts of magnesium and other microminerals. The purpose of this study was to investigate the degree to which the high levels of magnesium in seaweed calcium extract affects the calcium balance and the bone status in ovariectomized rats in comparison to rats supplemented with calcium carbonate and magnesium oxide. A total of 40 Sprague-Dawley female rats (7?weeks) were divided into four groups and bred for 12?weeks: sham-operated group (Sham), ovariectomized group (OVX), ovariectomized with inorganic calcium and magnesium supplementation group (OVX-Mg), and ovariectomized with seaweed calcium and magnesium supplementation group (OVX-SCa). All experimental diets contained 0.5% calcium. The magnesium content in the experimental diet was 0.05% of the diet in the Sham and OVX groups and 0.1% of the diet in the OVX-Mg and OVX-SCa groups. In the calcium balance study, the OVX-Mg and OVX-SCa groups were not significantly different in calcium absorption compared to the OVX group. However, the femoral bone mineral density and strength of the OVX-SCa group were higher than those of the OVX-Mg and OVX groups. Seaweed calcium with magnesium supplementation or magnesium supplementation alone did not affect the serum ALP and CTx levels in ovariectomized rats. In summary, consumption of seaweed calcium extract or inorganic calcium carbonate with magnesium oxide demonstrated the same degree of intestinal calcium absorption, but only the consumption of seaweed calcium extract resulted in increased femoral bone mineral density and strength in ovariectomized rats. Our results suggest that seaweed calcium extract is an effective calcium and magnesium source for improving bone health compared to synthetic calcium and magnesium supplementation.     

Enhancing effect of dietary vinegar on the intestinal absorption of calcium in ovariectomized rats.

We studied the effect of dietary vinegar on calcium absorption by using ovariectomized rats fed on a low-calcium diet. The apparent absorption of calcium was higher when the rats were fed on a diet containing 1.6% vinegar for 32 days than when fed on a diet without vinegar (P < 0.05). The calcium content in the femur of the rats given diets containing 0.4% and 1.6% vinegar were also higher (P < 0.05). The serum parathyroid hormone level was lower and the crypt depth of the duodenum thicker in the rats fed on a diet containing 1.6% vinegar (P < 0.05). These results suggest that dietary vinegar enhanced intestinal calcium absorption by improving calcium solubility and by the trophic effect of the acetic acid contained in vinegar, which would reduce the bone turnover caused by ovariectomy and be helpful in preventing osteoporosis.