亚急性硒中毒对小鼠睾丸组织细胞结构的影响

120只5~6周龄昆明小鼠被随机平均分为4组,试验组分别按0.135 mg/kg(1/80LD50)、0.54 mg/kg(1/20LD50)、2.16 mg/kg(l/5LD50)灌胃亚硒酸钠溶液,对照组灌胃蒸馏水,连续攻毒30 d,每隔10 d各组随机选取10只采样,并对睾丸组织进行光学和超微病理学观察。结果表明:亚急性硒中毒影响小鼠睾丸内生殖细胞的发育,高硒可严重损伤小鼠睾丸曲细精管、生精细胞及间质细胞。睾丸病理组织学观察和超微结构观察,均能检测到处于凋亡状态的生殖细胞,而且凋亡细胞的数量与染硒剂量和染硒时间有关。     

硒中毒对猪血清自由基的影响

通过在仔猪基础日粮中添加亚硒酸钠,然后定期检测猪血清中的部分自由基及相关指标,以观察自由基在硒中毒猪体内的变化规律.结果表明硒中毒时,猪血清内的丙二醛(MDA)、羟自由基(·OH)和一氧化氮(NO)的含量明显升高,而超氧化物歧化酶(SOD)则明显降低,一氧化氮合酶(NOS)和NO的变化规律一致.结果显示自由基与硒中毒有着密切的关系.     

镉对鸡抗氧化系统功能的影响及硒颉颃的效应

30只100日龄海兰公鸡随机分为对照组、加镉组、加硒镉组,对照组饲喂基础日粮,加镉组饲喂基础日粮 CdCl2150 mg/kg,加硒镉组饲喂基础日粮 CdCl2150 mg/kg Se 10 mg/kg,分笼常规饲养,试验期为60 d,复制出鸡亚慢性镉中毒及硒颉颃模型.试验结果显示,睾丸脏器系数为对照组、加硒镉组至加镉组依次降低;血清和睾丸中谷胱甘肽过氧化物酶(GSH-Px)活性为对照组、加硒镉组至加镉组依次降低,变化比较明显;血清和睾丸中超氧化物歧化酶(SOD)活性为对照组、加硒镉组至加镉组依次降低,变化比较明显;血清和睾丸中丙二醛(MDA)含量为对照组、加硒镉组至加镉组依次升高.揭示了镉对鸡抗氧化系统功能的影响,构成了镉损伤机体的病理学基础.补硒后可降低镉的损伤.     

硒对公鸡睾丸发育中毒形态学分析

150只海兰白公鸡雏分为5组,分别饲喂不同硒含量的日粮,I-V组日粮硒含量为1mg/kg、5mg/kg、10mg/kg、15mg/kg、20/mg/kg,在21周龄屠宰,观察睾丸组织结构。结果表明,I组发育最好,生精上皮细胞层数多、管壁厚,管径大,精子簇密集;II组到V组随硒浓度的增加中毒症状明显,生精细胞散乱,生精上皮脱落,精细管溶解。实验结果表明,公鸡日粮中含硒量以不超过1mg/kg为宜。     

亚急性硒中毒对小鼠精子质量的影响研究

为了研究亚急性硒中毒对小鼠精子质量的影响,试验选用雄性昆明鼠灌胃染毒。高、中、低剂量组分别按照0.135 mg/kg、0.540 mg/kg、2.160 mg/kg剂量浓度灌胃亚硒酸钠溶液,对照组灌胃纯化水,连续攻毒30 d,每隔10 d各组随机选取10只采样,检查睾丸脏器系数、精子密度、精子活率、精子畸形率。随着染硒剂量的增加和时间的延长,各染硒剂量组睾丸脏器系数呈下降趋势,小鼠精子密度和精子活率随染硒剂量的增加逐渐减小,各染硒组小鼠的精子畸形率均有增加,呈现明显的时间-剂量-效应关系。结果表明：亚急性硒中毒可影响雄性小鼠生长发育,阻碍睾丸的发育甚至引起睾丸萎缩,影响精子的生成和发育,降低雄性小鼠的生殖机能。     

酵母硒对蛋鸡血清酶活性及抗氧化能力的影响

为研究酵母硒对蛋鸡血清酶活性及抗氧化能力的影响,试验选用1 000只280日龄的海兰褐壳蛋鸡,随机分为5组,每组5个重复,每个重复40只,分别为基础饲粮组,以及0.1,0.2,0.3和0.4mg/kg酵母硒添加水平组,试验期40d。结果表明:与对照组相比,各试验组均可显著提高血清ALP和LDH活性(P<0.05),并显著降低CK活性(P<0.05);与对照组相比,饲粮添加0.2,0.4mg/kg酵母硒均可显著提高血清SOD活性(P<0.05),其他试验组SOD活性与对照组无显著性差异(P>0.05);各试验组GSH-Px和T-AOC水平均显著高于对照组(P<0.05),而血清MDA含量均显著低于对照组(P<0.05)。试验结果提示,酵母硒可提高蛋鸡抗氧化能力,且以添加0.3,0.4mg/kg为宜。     

不同水平的亚硒酸钠对公鸡组织硒沉积及血液抗氧化能力的影响

试验通过在公鸡日粮中添加不同水平亚硒酸钠,研究硒在公鸡组织中的沉积和对血液抗氧化能力的影响,为亚硒酸钠在鸡养殖业中的应用提供参考依据。选取80只体重接近、健康无疾病的海兰白成年公鸡,随机分成4组,每组20只,分别在日粮中添加0、0.5、1、2 mg/kg的亚硒酸钠。试验结束时,采集肝脏、肾脏、心、肺、脾、睾丸以及血液,测定硒含量,并分析血液中的谷胱甘肽过氧化物酶(GSH-Px)活性、超氧化物歧化酶(SOD)活性和总抗氧化能力(T-AOC)等。结果表明：组织和血液中硒含量随日粮硒含量的增加而升高,除心肌组织以外,各组之间差异显著（P<0.05）;血液中的SOD、T-AOC活性随着日粮硒含量的增加而逐渐增加,且各组之间差异显著（P<0.05）;适量的硒元素可以提高GSH-Px的活性,但过量的硒元素又会增加脂质过氧化反应,造成MDA含量升高,从而对组织细胞造成不良影响。结果提示：适量的硒可以提高鸡组织和血液中的硒含量,也可以提高血液的抗氧化能力,且提倡适宜的浓度为0.5 mg/kg。     

纳米硒对肉鸡肝脏硒含量和抗氧化能力的影响

试验选用1日龄艾维茵(Avian)肉鸡225只,随机分为5个处理组,每组设3个重复,研究纳米硒对肉鸡肝脏硒含量和抗氧化能力的影响。在玉米-豆粕型日粮基础上添加纳米硒0、0.15、0.3、0.6、1.2mg/kg,基础日粮组为对照组,试验期6周。结果表明:42日龄时,日粮中添加纳米硒显著提高了肝脏总抗氧化能力、谷胱甘肽过氧化物酶活力、总超氧化物歧化酶活力、抑制羟自由基能力(P<0.05),显著降低了肝脏丙二醛含量、一氧化氮含量(P<0.05),极显著提高了肝脏硒含量(P<0.01)。而且随日粮中纳米硒添加量的增加,肝脏抗氧化能力和硒含量均呈二次曲线关系。因此,肉鸡日粮中纳米硒的适宜添加水平为0.7～1.0mg/kg。     

酵母硒对肥育猪肉品质及抗氧化能力的影响

试验旨在研究不同水平的酵母硒对肥育猪胴体特性、肉品质及抗氧化能力的影响。选用72头体质量约70 kg的(杜×长×大)三元杂交肥育猪,随机分为4个处理,各处理饲粮中分别添加0(对照组)、0.10、0.30和0.50 mg/kg酵母硒,试猪体质量约100 kg时结束试验。结果表明:饲粮添加不同水平酵母硒均未改善肥育猪的屠宰率、肌内脂肪、大理石花纹、眼肌面积和剪切力(P>0.05);不同水平的酵母硒均未显著影响肥育猪背最长肌pH45 min和pH24 h;各处理组背最长肌滴水损失均显著低于对照组,其中0.3 mg/kg酵母硒可改善肉色(P<0.05);不同水平的酵母硒能极显著地提高血清谷胱甘肽过氧化物酶(GSH-Px)水平,可显著提高总抗氧化能力(T-AOC)及总超氧化物歧化酶(T-SOD)和过氧化氢酶(CAT)的含量,0.3 mg/kg酵母硒显著降低丙二醛(MDA)水平。综合考虑,日粮硒水平为0.30 mg/kg的酵母硒添加组效果较好。     

钼中毒对绵羊机体抗氧化能力的影响

将体重(21±3)kg左右的10只卡拉库尔羊随机分成2组,试验组按每天以30 mg/kg体重灌服钼,对照组灌服等体积的去离子水,试验期为60 d,每隔15 d检测血清超氧化物歧化酶(SOD)和总抗氧化能力(T-AOC)的活力值,以及丙二醛(MDA)的含量,以观察其动态变化。结果表明试验组的血清SOD和T-AOC活力值显著低于对照组(P<0.05),而MDA的含量显著高于对照组(P<0.05)。实验结果提示钼中毒会导致卡拉库尔羊机体的抗氧化能力降低。     

亚急性乌头碱中毒对小鼠血液生理指标的影响

为了探讨乌头碱对小鼠血液生理指标的影响,将120只小鼠随机分成4组,即对照组(生理盐水)、低剂量组(0.14μmol/L)、中剂量组(0.28μmol/L)、高剂量组(0.56μmol/L),连续灌胃30d。分别在10,20,30d每次每组随机采集10只小鼠血液,用全自动血液细胞分析仪测定血液中白细胞(WBC)、淋巴细胞(LymPh)、单核细胞(Mon)、中心粒细胞(Gran)、红细胞(RBC)、血红蛋白(HGB)、红细胞压积(HCT)和血小板(PLT)的含量。结果显示,高剂量组小鼠肝脏、肺脏、大脑的脏器系数明显增加(P0.05或P0.01)。随毒物浓度的增加,各染毒组WBC、LymPh、Mon、Gran先升高后降低,与对照组相比,高剂量组变化最为明显,且差异显著(P0.05或P0.01)。RBC、HGB、HCT和PLT持续降低,在20和30d时,除低剂量组外,差异显著(P0.05或P0.01)。结果表明,不同浓度乌头碱对小鼠血液生理指标有显著影响,且存在明显时间和剂量效应关系,可引起动物贫血,降低机体免疫机能。     

亚急性硒中毒对小鼠巨噬细胞与抗体形成细胞的影响

为探讨亚硒酸钠染毒对小鼠免疫功能的影响,将试验动物分为阴性对照组(0.00mg/kg体重.d)、亚硒酸钠低剂量组(0.14mg/kg体重.d)、中剂量组(0.54mg/kg体重.d)和高剂量组(2.16mg/kg体重.d)。连续灌胃30d后处死小鼠,分别用巨噬细胞吞噬鸡红细胞试验与溶血空斑试验检测小鼠腹腔巨噬细胞的吞噬功能与抗体形成细胞的数量。结果显示,亚硒酸钠染毒使小鼠巨噬细胞的吞噬功能与抗体形成细胞的数量显著降低,且与染毒剂量具有相关性。表明亚硒酸钠染毒可抑制小鼠非特异性免疫功能,呈现明显剂量效应关系。     

小鼠亚急性乌头碱中毒的脏器系数和血液生化指标分析

为了探讨乌头碱对小鼠血液生化指标及脏器系数的影响,120只小鼠被随机分成4组,即对照组(生理盐水)、低剂量组(0.14μmol/L)、中剂量组(0.28μmol/L)、高剂量组(0.56μmol/L),连续灌胃30 d。分别于第10、20、30天每次每组随机采集10只小鼠血液,用全自动生化分析仪测定乌头碱对小鼠血清ALT、AST活性及BUN、CRE、TC、TG、TP、ALB、GLU含量的影响,并于第30天时采集小鼠大脑、小脑、心、肝、脾、肺、肾。结果显示,各攻毒组小鼠均表现不同程度的中毒症状,且平均体重增长趋势均低于对照组。高剂量组小鼠肝、脾、肺、大脑的脏器系数明显改变(P0.05或P0.01)。随攻毒浓度的增加,各染毒组BUN、TC、GLU含量及ALT、AST活性呈升高趋势,与对照组相比,除低剂量组外,差异显著(P0.05或P0.01),CRE、TG含量先降低后升高,TP、ALB含量持续降低,部分组间差异显著(P0.05)。结果表明,不同剂量乌头碱对小鼠脏器系数和血液生化指标有显著影响,且存在明显时间和剂量效应关系。     

Effects of amino acid balance and energy: Protein ratio on energy and nitrogen metabolism in male broiler chickens

1. An experiment was performed with growing broiler chickens (14 to 21 d old) to examine 3 diet characteristics which have been implicated in regulatory elevation of metabolic rate: an unbalanced amino acid mixture, high dietary energy concentration and low protein concentration.

2. Differences in energy expenditure could be explained almost entirely (93%) by differences in quantities, and therefore costs, of protein and fat accretion. There was no indication of regulatory diet‐induced thermogenesis. Heat production was not significandy correlated with CP:TME ratio and was negatively correlated (P<0.01) with dietary TME concentration.

3. Heat production was closely correlated (P< 0.001) with rate of protein accretion, which in turn was more strongly associated with intake of the first‐limiting amino acid (lysine) than with total protein intake. Heat production on an imbalanced, lysine‐limited, amino acid mixture was no greater than on a balanced amino acid source with the same lysine concentration.

4. There was no indication of a stimulation of heat production by excess amino acids. Heat production, adjusted for body weight by covariance analysis, was similar on paired diets which had identical lysine concentrations but a 1.5‐ or 2‐fold difference in crude protein concentration.

5. There was a strong negative correlation (P< 0.001) between protein retention per g of lysine consumed and lysine :CP ratio, suggesting that, in this case, response to a limiting amino acid was improved by the presence of a super‐abundance of other amino acids.     

Effects of riboflavin supplementation and selenium source on selenium metabolism in the young pig

The effect of dietary riboflavin (B2) supplementation and selenium (Se) source on the performance and Se metabolism of weanling pigs was studied. Pigs fed a B2-supplemented (10 mg/kg) casein-glucose diet for 18 d gained faster than pigs fed the B2-unsupplemented diet. Percentage active erythrocyte glutathione reductase (GR) declined rapidly when pigs were placed on the B2-unsupplemented diet and was lower (P less than .01) than that of B2-supplemented pigs after 12 d on test. Percentage active erythrocyte GR values fell below 50% before other B2 deficiency signs became evident. Supplementation of diets with 10 mg B2/kg resulted in increased kidney and muscle glutathione peroxidase (GSH-Px) activity. The Se concentration of liver and heart increased and plasma Se levels decreased with dietary B2 supplementation. Riboflavin supplementation and Se source did not alter apparent Se absorption, but B2 supplementation decreased urinary Se and thus increased Se retention. Also, there was less urinary Se excretion when selenomethionine was the dietary Se source and consequently more Se was retained than when sodium selenite was the dietary Se source. In a final trial, B2 supplementation increased kidney, muscle, heart and brain GSH-Px activity when sodium selenite was the dietary Se source, but not when selenomethionine was the dietary Se source.     

氟对不同日龄雄性大鼠睾丸组织中表皮生长因子及其受体表达的影响

为探讨氟对不同日龄雄性Wistar大鼠睾丸组织中表皮生长因子（EGF）及其受体（EGFR）表达的影响,选用40日龄雄性Wistar大鼠200只,随机分为2组分别饮用含150mg/L氟化钠的去离子水和去离子水,并于50,80,100,120日龄时处死大鼠,对睾丸组织中EGF及其EGFR的表达情况进行分析。结果表明,染氟组50日龄时睾丸组织间质细胞、精原细胞和生精细胞中EGF的表达量极显著下降（P〈0.01）,精子细胞和管腔脱落物中EGF的表达量降低不明显（P〉0.05）;80,100,120日龄时虽有下降趋势,但无统计学意义（P〉0.05）。而染氟组睾丸组织中EGFR的表达量在50,80,100日龄时均降低,但50,80日龄睾丸组织精子细胞和100日龄睾丸组织曲细精管管腔脱落物中EGFR的表达量极显著下降（P〈0.01）,50日龄时生精细胞中EGFR的表达量显著降低（P〈0.05）;而120日龄时睾丸组织中EGFR的表达量均增高,且管腔脱落物中极显著增高（P〈0.01）。证明氟可降低雄性Wist-ar大鼠性成熟时EGF的表达量以影响精子的生长发育,长期抑制EGF的表达使EGFR的表达增高影响生殖功能。     

槲皮素对双酚A致小鼠生精功能障碍的治疗作用

将50只雄性昆明小鼠随机分为5组,A组（n=10）正常喂饲,B、C、D、E组（各10只）小鼠均腹腔注射50mg／kg·d的BPA,1次／d,连续注射7d,构造小鼠睾丸损伤模型,同时C、D、E组分别用100、200、400mg／kg·d浓度的Que灌胃7d,A组和B组给予等量生理盐水。记录小鼠的体征、体质量变化及试验结束时睾丸、附睾和精囊腺的质量;试剂盒检测血清中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GsH—Px）和丙二醛（MDA）的含量;酶联免疫法测定血清睾酮（T）、黄体生成素（LH）和促性腺激素释放激素（GnRH）的水平;对睾丸组织进行组织学观察。结果显示：D组200mg／kg·d小鼠体质量、各脏器质量均较B组有明显改善（P〈O．05或P〈0．01）,接近A组,C组和E组只有附睾质量变化显著（P〈0．05）;Que各剂量组血清中的SOD、GSH—Px活性均高于BPA组,差异极显著（P〈0．01）,其中D组抗氧化酶的活性最高;MDA测定结果显示,D组明显降低,差异极显著（P〈0．01）,E组也有所降低,差异显著（P〈0．05）;C、D、E组小鼠血清生殖激素水平均有一定程度的恢复,但D组各生殖激素指标均接近A组;组织学观察见各给药组睾丸生精小管生精细胞层数、精子数目均高于B组,尤以D组200mg／kg·d恢复最为明显。结果表明：Que能够促进BPA致小鼠睾丸生精功能障碍后生精功能的恢复,且最佳剂量为200mg／kg·d。     

Effects of dietary fat type and xylanase supplementation in rye containing diets on energy metabolism in male broilers

Xylanase supplementation of rye-based diets which contained 10% beef tallow was shown to markedly improve the digestibility of fat whereas the enzyme effect in diets containing 10% soya oil was much less pronounced (Dänicke et al. 1997b). Such interactions between fat type and xylanase supplementation have also been reported for wheat–rye-based diets (Langhout et al. 1997) and wheat-based diets (Allen et al. 1997) and were attributed mainly to the fatty acid composition of different types of fat and to changes in digesta viscosity caused by soluble pentosan. The apparent metabolizable energy, N-corrected (AME_N) contents of such diets were affected in a similar manner suggesting that energy metabolism is also influenced by xylanase supplementation and the type of dietary fat. However, changes in the metabolizability of gross energy does not necessarily indicate whether the efficiency of metabolizable energy (ME) for energy gain is changed nor if different proportions of ME are used for maintaining an energy equilibrium, i.e. ME maintenance requirement. In addition, studies suggest that both dietary fat level and fat type might exert effects on the efficiency of utilization of ME for energy retention (Carew and Hill 1964; de Groote et al. 1971; Fuller and Rendon 1979; Brue and Latshaw 1985). Hence, the aim of this study was to investigate the partitioning of ME between maintenance needs and energy retained as protein and as fat when feeding rye-based diets. The diets contained either soya oil or beef tallow and were either unsupplemented or xylanase-supplemented.     

包被硒对西门塔尔牛日粮营养物质消化代谢的影响

选用4头装有永久性瘤胃瘘管的西门塔尔阉牛,采用4×4拉丁方设计,研究包被硒(0、0.3、0.6和0.9mg/kgDM)对日粮营养物质消化代谢的影响。结果表明:0.6mg/kg组日粮养分的表观消化率显著高于对照组(P<0.05);日粮DN、RN、RN/DN显著高于对照组(P<0.05),以0.6mg/kg组最高;0.6mg/kg组Se、Ca、P、Cu、Fe和Mn的存留率均显著高于对照(P<0.05)。兼顾基础日粮含硒量,建议以包被硒为硒源时日粮硒水平为0.67mgSe/kgDM。     

Alterations of gene expression in adult male rat testis and pituitary shortly after subacute administration of the antiandrogen flutamide

In the course of profiling alterations of gene expression in the male reproductive system induced by anti-androgenic agents, 28 genes expressed in the testis or pituitary of adult rats were examined shortly after subacute administration of the well-known anti-androgen, flutamide (FM). FM (25 mg/kg/day) was orally administered to male rats for six days. On day 8 (D8) after the first dose of FM, intratesticular testosterone (T) levels had dramatically increased, but daily sperm production on D36 was significantly decreased. The mRNA levels of testicular and pituitary genes on D8 were measured by semiquantitative RT-PCR. Among the six testicular steroidogenic enzyme genes, the mRNAs of the P450 side chain cleavage, P450 17 alpha/C(17-20) lyase, and 3beta-hydroxysteroid dehydrogenase type I (3betaHSD) genes significantly increased, whereas 17beta-hydroxysteroid dehydrogenase type III slightly decreased. Among the three steroid receptors examined, androgen receptor (AR) and glucocorticoid receptor (GR) mRNAs were significantly down-regulated (29% and 35%, respectively) in the testis, but there was no change in estrogen receptor alpha. There were no clear changes in expression of the gonadotropin receptors and Sertoli cell specific genes, but a slight increase was observed in expression of the lactose dehydrogenase-c mRNA, a germ cell specific gene. Among the three immediate early genes, c-myc mRNA was increased approximately 1.4-fold. In the pituitary, on the other hand, mRNAs for LHbeta and FSHbeta subunits and gonadotropin releasing hormone receptor had increased significantly. These results show that subacute FM administration first affected hypothalamus/pituitary hormone gene expression, then altered gonadotropin secretion, and subsequently induced over-expression of testicular steroidogenic enzyme genes. However, the significant up-regulation of 3betaHSD and down-regulation of AR mRNAs, despite the higher level of intratesticular T, might be explained by an antagonistic action of hydroxyflutamide retained in the testis. The profiles of alterations in gene expression observed will provide important information for the screening of adult male animals for anti-androgenic chemicals.