不同毒力鸭肝炎病毒对雏鸭肝脏抗氧化功能的影响

用不同毒力株鸭肝炎病毒感染雏鸭复制病理模型 ,研究雏鸭感染病毒性肝炎后肝脏抗氧化功能的变化。将 16 0只刚出壳的北京鸭 ,经 1周适应性饲养后 ,随机均分为对照组、弱毒株组、中毒株组和强毒株组。在攻毒组的每只雏鸭背部分别肌肉注射 0 .3m L弱毒株、中毒株和强毒株的稀释液。攻毒后 1、3、5、7d剖杀雏鸭 ,采集其肝组织 ,测定鸭肝组织中过氧化氢酶 (CAT)、谷胱甘肽过氧化物酶 (GSH- Px)及超氧化物歧化酶 (SOD)的含量。结果表明 ,中毒组和强毒组的 CAT含量在攻毒后 1d便显著或极显著低于对照组 ,但弱毒株组在攻毒后的 5 d才显著低于对照组。攻毒后1d,雏鸭肝组织中 SOD含量开始下降 ,3d后显著或极显著低于对照组。攻毒后 5 d,各攻毒组雏鸭肝组织中的 GSH-Px的含量亦显著降低。这些抗氧化酶含量的降低 ,说明感染鸭肝炎病毒后雏鸭清除自由基的能力下降 ,自由基参与了鸭病毒性肝炎的发病过程。     

Ovarian inhibition of peripheral plasma concentration of follicle stimulating hormone in prepuberal Holstein heifers

The objective of this study was to determine effects of age and castration on follicle stimulating hormone (FSH) secretion in prepuberal heifers. In experiment 1, twelve heifers were bilaterally ovariectomized at 3, 6, or 9 months of age (n = 4/group). Blood was collected at 10 min intervals for 8 hr at 1 week before ovariectomy and 1 and 4 weeks after ovariectomy. Frequency, amplitude and duration of FSH pulses were calculated. Mean plasma concentration of FSH (ng/ml), and frequency (pulses/8 hr), amplitude (ng/ml), and duration (min/pulse) of FSH pulses were not altered by age. Mean concentration of FSH increased (P less than .01) from 1 week before to 1 week and 4 weeks after ovariectomy, respectively, in all age groups. Pulse frequency increased (P less than .05) from 1 week before ovariectomy to 4 weeks after ovariectomy in 3 month old heifers, from 1 week before to 4 weeks after ovariectomy in 6 month old heifers, and from 1 week before to 1 week and 4 weeks after ovariectomy in 9 month old heifers. In experiment 2, twelve heifers were bilaterally ovariectomized at 3, 6 or 9 weeks of age (n = 4/group). Sample collection and measurement of mean concentration of FSH were the same as in experiment 1. Mean concentration of FSH increased (P less than .01) from 1 week before to 1 and 4 weeks after ovariectomy in heifers ovariectomized at 6 and 9 weeks of age.(ABSTRACT TRUNCATED AT 250 WORDS)     

维生素A对0～12周龄青农灰鹅抗氧化性能的影响

选用1日龄青农灰鹅200只,随机分为5个处理,每处理4个重复,每重复10只。在玉米-豆粕型日粮基础上分别添加0（处理Ⅰ）、1 500（处理Ⅱ）、3 000（处理Ⅲ）、6 000（处理Ⅳ）和12 000IU/kg（处理Ⅴ）的维生素A,试验期12周。分别测定了第4、12周龄青农灰鹅血清和肝脏中GSH-Px、T-SOD、CAT活性、抑制羟自由基（.OH）能力、抗超氧阴离子自由基（O2-.）活性、MDA含量和T-AOC。结果显示,基础日粮中添加维生素A能够显著提高4周龄青农灰鹅血清和肝脏SOD活力、T-AOC、抗超氧阴离子自由基（O2-.）活性和抑制羟自由基（.OH）能力,降低MDA含量（P〈0.05或P〈0.01）;显著提高血清GSH-Px、CAT活力（P〈0.05）。12周龄显著提高血清和肝脏GSH-Px、SOD活力、抗超氧阴离子自由基（O2-.）活性和抑制羟自由基（.OH）能力（P〈0.05或P〈0.01）,降低MDA含量（P〈0.05或P〈0.01）;显著提高血清CAT和T-AOC活力（P〈0.05）。结果表明,日粮中添加维生素A可显著提高青农灰鹅血清和肝脏的抗氧化性能,增强抗氧化酶活性,降低自由基的产生。综合各项指标,本试验条件下,0～4、5～12周龄日粮维生素A添加水平均以6 000IU/kg为宜。     

肝片吸虫感染对山羊机体自由基代谢影响的研究

实验选择9只健康、6－10月龄雄性白山羊，经粪便学检查和Dot-ELISA检测，确认无肝片吸虫感染，随机分成感染组（n=5)和对照组（n=4)，试验组每只1次口服接种150个肝片吸虫囊蚴，每周定时从颈静脉采集感染前（0周）和感染后15周血液1次分离血清。测定血清谷胱甘肽过氧化物酶（GSH－Px)活性、超氧化物歧化酶（SOD）活性、过氧化物酶（CAT）活性、丙二醛（MDA）和一氧化氮含量的变化，结果表明肝片吸虫感染后血清中GSH－Px活性除第8周试验组显著高于对照组，其他各周无显著差异；在整个实验期间，试验组山羊血清中SOD活性在1－5周呈波动状，以后两组基本处于同一水平；试验组山羊血清CAT活性在感染后第3周显著低于对照组，第6－15周时，试验组始终高于对照组，但各周差异均不显著；试验组山羊血清中MDA含量在整个实验期间始终呈波动状，而在第8、9周试验组显著高于对照组，中周与对照组相比无显著差异；感染后试验组血清中NO开始下降，并且显著低于对照组，至第3－6周时试验组显著高于或低于对照组，第6－15周，试验组一直高于对照组，并在第7、10周时显著地高于对照组。提示山羊感染肝片吸虫后，机体发生多种功能的改变，机体的自由基产生与清除处于相互对抗之中，机体的自由基代谢参与了肝片吸虫病的发展过程。     

The comparison of antioxidative/oxidative profile in blood, colostrum and milk of early post-partum cows and their newborns

Act of delivery is supposed to be connected with antioxidative/oxidative imbalance not only in female but also in her newborn. The aim of the study was to compare antioxidative/oxidative profile of cows and their newborns in blood, colostrum and milk during early post-partum period. Twenty-five healthy pregnant cows and their newborns were included into study. Blood and colostrum/milk samples were obtained immediately after parturition, 24, 48 h as well as 6 and 12 days post-partum. Parameters of antioxidative defence including total antioxidant capacity (TAC) and glutathione peroxidase (GSH-Px) as well as parameters of lipid (LPI) and protein (SH) peroxidation intensity were determined spectrophotometrically. Obtained results indicated dynamic changes in values of examined parameters during time of experiment, which were significantly marked between 24 and 48 h post-partum, and the relationship between mother and her newborn. All parameters except for GSH-Px were markedly higher in blood of newborns as in their mothers. Moreover, TAC and GSH-Px in colostrum were lower as in blood of mothers and their newborns during first 24 h and showed opposite relationship later on. LPI was higher in colostrum as in plasma of mothers and their newborns during first 48 h, while SH was lower in colostrum as in plasma of examined animals. Values of antioxidative parameters increased significantly within examined period of time, while the content of SH groups tended to decrease and lipid peroxidation intensity fluctuated. Dynamics in changes of examined parameters may suggest temporary imbalance in antioxidative/oxidative status and adequate answer of organism to current challenge resulting from overproduction of reactive oxygen species. Present study may bring new knowledge into studies of post-parturient and post-natal period in cows and calves and may help preventing from diseases of this period.     

水牛感染肝片吸虫后红细胞免疫功能的变化

选择２０头２－３岁、体重３００－４００ｋｇ健康雄性去势水牛,经粪便检查和Ｄｏｔ－ＥＬＩＳＡ检测确认为无肝片形吸虫感染后进行两个系列的实验。第一系列实验８头水牛随机分成感染组（ｎ＝５）和对照组（ｎ＝３）,感染组每头水牛每天口服６０个囊蚴,连续２０天,共感染１２００年囊蚴,研究慢性感染方式对机体红细胞免疫功能的影响;第二系列实验１２头水牛随机分成感染组（ｎ＝９）和对照组（ｎ＝３）,感染组每头水牛１次性     

The role of antioxidant vitamins (C and E), selenium and Nigella sativa in the prevention of liver fibrosis and cirrhosis in rabbits: new hopes

This experiment was carried out to investigate the role of antioxidants such as vitamin C and E, selenium and Nigella sativa (NS) on the prevention of carbon tetrachloride (CCl4)-induced liver fibrosis in rabbits. It was found that superoxide dismutase (SOD) values in all of the treated groups were significantly lower than those of the control at 12th week of experiment (p < 0.05), while at 6th week and 12th week of experiment glutathione peroxidase (GSH-Px) values in the vitamin C treated group were significantly different from the control (p < 0.05). Histopathologically, hepatocellular necrosis, degeneration and advanced fibrosis were found in the control group. Lesions were minor and only confined to midzonal regions without centrilobular necrosis and fibrosis in the NS treated animals (group B). The lesions observed in the vitamin C treated animals (group C) were similar to that of the control group. Parenchymal changes with fibrosis were less in selenium and vitamin E treated animals (group D) than in those of the control group, but more obvious than in NS group. Histopathological findings demonstrate that NS might, at least partly, be successful in the prevention of liver fibrosis in rabbits. Vitamin E plus selenium had little therapeutic effect and vitamin C seemed to be ineffective, as far as the results of this study are concerned.     

饲粮维生素D添加水平对蛋雏鸭免疫及抗氧化功能的影响

本试验旨在研究饲粮维生素D添加水平对1～28日龄蛋雏鸭免疫及抗氧化功能的影响,以探讨饲粮维生素D的适宜添加量。试验选取健康、体重相近的1日龄金定蛋雏鸭180只,随机分为5组(Ⅰ～Ⅴ组),每组6个重复,每个重复6只试鸭。采用玉米-豆粕型基础饲粮,Ⅰ组(对照组)试鸭饲喂基础饲粮,Ⅱ～Ⅴ组试鸭分别饲喂在基础饲粮中添加110、220、550、1 000 IU/kg维生素D的试验饲粮,试验期4周。结果表明:饲粮添加550 IU/kg维生素D可显著提高胸腺指数、脾脏指数(P<0.05),并显著增强肝脏超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性(P<0.05),降低血清白细胞介素-2(IL-2)及血清和肝脏丙二醛(MDA)含量(P<0.05);饲粮添加220、550 IU/kg维生素D可显著提高血清总蛋白(TP)和白蛋白(ALB)含量(P<0.05),并显著增强血清SOD和GSH-Px活性及血清和肝脏总抗氧化能力(T-AOC)(P<0.05)。综合本试验结果,在玉米-豆粕型基础饲粮中添加适量的维生素D可提高1～28日龄蛋雏鸭的免疫及抗氧化功能。综合考虑各指标,通过二次回归模型估测得出维生素D适宜添加量为512.8～550.0 IU/kg。     

Evaluation of antioxidant status and oxidative stress in sheep naturally infected with Babesia ovis

The present study aimed to assess antioxidant status and oxidative stress in sheep naturally infected with Babesia ovis. Red blood cell (RBC) count, hemoglobin (Hb) concentration, packed cell volume (PCV), piroplasm parasitemia percentage, malondialdehyde (MDA) concentration, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) activities and total antioxidant capacity (TAC) were determined in 52 sheep naturally infected with B. ovis as well as same number of healthy sheep in West-Azerbaijan province, Iran. Microscopic examination of Giemsa-stained peripheral blood smears revealed B. ovis infection. The parasitological diagnosis was confirmed using polymerase chain reaction (PCR) analysis by amplifying a partial small subunit ribosomal RNA (ssu rRNA) gene sequence of B. ovis of 52 diseased sheep, 18 (34.61%), 11 (21.15%), 16 (30.76%) and 7 (13.48%) had <1%, 1-2%, 2-3% and >3% parasitemia, respectively. Compared to controls, the activities of erythrocyte GSH-Px, SOD, TAC and CAT showed a significant decrease, whereas the concentration of MDA in erythrocytes of infected sheep increased significantly. Parasitemia rate was positively correlated with MDA and negatively correlated with PCV, SOD, CAT, GSH-Px and TAC. Also, MDA was negatively correlated with PCV, SOD, catalase, GSH-Px and TAC. The study demonstrated that B. ovis plays an important role in the occurrence of oxidative damage to RBCs and anemia in ovine babesiosis.     

Effects of Gymnadenia Conopsea Polysaccharide Extract on Growth Performance,Antioxidant Function and Meat Quality of House-fed Mutton Sheep under Oxidative Stress

The purpose of this experiment was to study the effects of Gymnadenia conopsea polysaccharide (GCP) extract on growth performance, meat quality and antioxidant function house-fed mutton sheep under oxidative stress, so as to provide experimental basis for extensive research and development of Gymnadenia conopsea and its extracts. Twenty 6-month-old healthy male Small-Tailed Han sheep with body weight of (35.0 ±4.0) kg were randomly divided into two groups. The experimental group (n=10) and control group(n=10). The whole experiment lasted for 42 d and was divided into 3 periods: the first 15 days were the blank period; the middle 15 days were the treatment period; the last 12 days were the observation period ofter modeling. From the first day of the treatment period, the control group was fed with basal diet, and the experimental group was fed pellet basal diet containing 30 mg·kg^-1 GCP extract. On the 15th day of the treatment period, the sheep in each group were intraperitoneally injected with 10 mg·kg^-1 Diquat solution according to sheep body weight(BW), and then fed for another 12 days. On the 1 st, 15th, 30th, 33rd, 36th, 39th and 42nd morning of the whole experimental period, fasting weight and blood samples were collected before feeding. The serum was separated and the antioxidant indexes (SOD, GSH-Px, T-AOC, MDA) in serum were determined. On the 42nd day of the whole experimental period, 5 sheep randomly selected from each group were slaughtered and meat samples were collected to determine the meat quality. The results showed that the addition of GCP extract to the diet of the sheep could increase the average daily feed intake (P<0.05). When the body was subjected to oxidative stress, the indexes of daily gain and antioxidant enzymes recovered rapidly on experimental group, the mutton drip loss decreased significantly, and the mutton sheer force increased significantly(P<0.05). The results indicated that GCP extract could improve the growth performance of mutton sheep, and alleviated the decline of growth performance and antioxidant performance caused by oxidative stress, and had a certain effect of antioxidant stress.     

The effect of raloxifene on coronary arteries in aged ovariectomized ewes

BACKGROUND: Ovariectomized sheep are a useful model of postmenopausal osteoporosis and other postmenopausal conditions. Estrogen may have a protective effect on the coronary arteries in postmenopausal women. The effects of raloxifene, a selective estrogen receptor modulator, on coronary arteries in aged ovariectomized ewes was investigated. METHODS AND RESULTS: Forty eight aged ewes were randomly assigned to undergo sham surgery (Sham, n = 7), ovariectomy (OVX, n = 10), ovariectomy with estradiol supplementation (OVXE, n = 8), ovariectomy with raloxifene supplementation, 0.02 mg/kg per day (RAL1, n = 10), or ovariectomy with raloxifene supplementation, 0.10 mg/kg per day (RAL2, n = 13). Contrast coronary angiography was performed 6 months after intervention. Diameters of the right main and left anterior descending coronary arteries in the RAL1, RAL2 and Sham groups were not different from each other, but were significantly greater than the OVX and OVXE groups. Intracoronary nitroglycerin did not affect the relationships of the diameters in any group. There were no differences in vascular remodeling between the groups. CONCLUSIONS: The results indicate that raloxifene in this sheep model allows greater dilation of coronary arteries than estrogen. Raloxifene may provide a significant protective functional effect on coronary arteries in postmenopausal heart disease.     

饲料中镉含量对蛋鸡生产性能及抗氧化功能的影响

为研究日粮中低剂量镉对蛋鸡生产性能和血清、肝肾抗氧化能力的影响,将192羽巴布考克B300蛋鸡随机分为4组,每组3个重复。对照组饲喂玉米-豆粕型基础日粮,试验组日粮为在基础日粮中分别添加5、10、20 mg/kg的镉(氯化镉形式,CdCl2.2.5H2O),试验期9周。结果表明:在1～3、4～6、7～9周,试验组的产蛋率、日采食量均低于对照组(P>0.05);各组在第7～9周时的采食量显著低于1～3周(P<0.05);血清中GSH-Px、GST、GR酶活力对镉不敏感(P>0.05),随镉添加量升高肝肾中GSH-Px活力先升后降,试验组肝肾中总巯基含量较对照组有显著升高(P<0.05);血清和肝肾中总SOD、CuZn-SOD、CAT活力随镉添加量升高呈先升后降的趋势;血清和肝肾中MDA、NO含量随着镉添加量的升高显著升高(P<0.05),总抗氧化能力均呈下降趋势。试验结果证实,镉可引起产蛋鸡体内抗氧化功能受损,机体产生氧化应激,并可能由此导致蛋鸡的生产性能下降。     

Progestins in Mid- to Late-Pregnant Mares

Two experiments were conducted to determine when a placental source of progestin was sufficient for maintaining pregnancy in the mare. In the first study, embryos were transferred into ovariectomized mares and pregnancy was maintained with altrenogest^a Altrenogest treatment was terminated at either day 100 (n=6) or day 150 (n=6). Twelve ovarian-intact mares were assigned to a second experiment on day 100 of gestation. On day 160 of gesta- tion, these mares were assigned to one of three treatments: 1) ovariectomy on day 160 and given altrenogest to day 200 (n=4); 2) ovariectomy on day 180 and given altrenogest to day 250 (n=4); or 3) ovariectomy on day 200 and given altrenogest to day 300 (n=4). Blood samples were collected every 2 weeks from all mares in both experiments from day 100 to parturition and assayed for concentrations of pro- gestins. Pregnancy loss from day 100 to parturition was not different among groups in either experiment. Serum con- centrations ofprogestins in ovary-intact mares were greater (P<0.05) than those in ovariectomized pregnant mares until day 130, after which they were similar. Serum con- centrations of progestins in the ovariectomized pregnant mares rose gradually from day 100 until near parturition. Serum concentrations of progestins in the ovary-intact pregnant mares declined from day 100 to day 157, did not vary significantly from day 157 to day 245, then rose until near parturition. Serum concentrations ofprogestins tended to decrease the sixth day prior to parturition. From these     

Serum concentrations of pituitary and adrenal hormones in female pigs exposed to two photoperiods

Serum concentrations of pituitary and adrenal hormones were determined in lactating sows and ovariectomized (OVX) gilts exposed to 8 h (8L:16D) or 16 h of light (16L:8D). In addition serum prolactin (PRL) concentrations were determined after a thyrotropin releasing hormone (TRH) challenge. At 103 +/- 2 d of gestation or 3 wk after ovariectomy of nulliparous gilts on d 7 to 9 of the estrous cycle (d - 10), blood samples were collected from jugular vein cannulae at 30-min intervals for 8 h beginning at 0800 h. Immediately after the last sample, 13 sows and five OVX gilts were assigned to 8L:16D and 14 sows and five OVX gilts were assigned to 16L:8D/d and placed in two identical chambers in the farrowing house. Blood sampling was repeated on d 7, 14 and 21 of lactation in the sows and on d 7, 14, 21 and 28 in the OVX gilts. In Exp. 1, serum cortisol (C) concentrations were similar for sows exposed to 8L:16D (n = 7) and 16L:8D (n = 6) treatments, whereas in Exp. 2, serum C concentrations for sows exposed to 8L:16D (n = 6) were lower than those exposed to 16L:8D (n = 6) on d 7, 14 and 21. Photoperiod failed to influence serum concentrations of PRL, luteinizing hormone (LH) and growth hormone in the lactating sows or PRL in the OVX gilts. Photoperiod also failed to affect mean basal serum concentrations, peak height and peak frequency for PRL and LH in the lactating sows or for PRL in the OVX gilts.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum Profiles of Pregnancy-Associated Glycoprotein, Oestrone Sulphate and Progesterone During Gestation and Some Factors Influencing the Profiles in Ethiopian Borana and Crossbred Cattle

This study presents serum concentrations of pregnancy‐associated glycoprotein (PAG), oestrone sulphate (E1‐S) and progesterone (P4), and the effects of some dam and foetus‐related factors on these profiles during gestation in Borana and crossbred cattle. The PAG concentrations at 4th week post‐conception ranged from 1.5–5.5 and 2.1–4.7 ng/ml in Borana (n = 6) and crossbred (n = 8) cattle, respectively. The mean PAG concentrations increased progressively from 4th to 33rd week of gestation (from 3.3–173 ng/ml for Borana and 4.2–240 ng/ml for crossbred cattle) and reached peak around calving. Breed, parity status, dam body weight, foetal sex and foetal birth weight significantly influenced the PAG concentrations. After delivery, the PAG concentrations declined steadily to 5.7 ng/ml in Borana (n = 7) and 3.9 ng/ml in crossbred (n = 6) cattle 10 weeks post‐partum. The serum E1‐S concentrations at 17th week of pregnancy ranged from 0.3–2.6 and 0.9–5.7 ng/ml in Borana (n = 8) and crossbred (n = 9) cattle, respectively. The mean E1‐S concentrations increased progressively from 17th to 33rd week of gestation (from 1.1–4.6 ng/ml for Borana and 2.7–10.8 ng/ml for crossbred). Breed, parity status, dam body weight and foetal sex significantly influenced E1‐S concentrations. The P4 concentrations at 4th week of pregnancy ranged from 3.2–5.1 and 1.7–8.9 ng/ml in Borana (n = 6) and crossbred (n = 8) cattle, respectively. The P4 level remained elevated throughout pregnancy. This study indicated that the serum PAG and P4 concentrations at 4th and E1‐S approximately 17th week of pregnancy were above the cut‐off value for pregnancy test and the hormonal profiles observed were comparable to the previous reports. Furthermore, the PAG and E1‐S profiles were considerably influenced by factors such as breed, weight and parity status of the dam, and foetal sex and foetal birth weight (only PAG).     

复方当归制剂对慢性氟中毒大鼠抗氧化系统的影响

采用Wistar大鼠复制慢性氟中毒模型,口服不同剂量的复方当归制剂,探讨其对慢性氟中毒大鼠的颉颃作用机理。检测各组大鼠血浆超氧化物歧化酶和谷胱甘肽过氧化物酶活性以及丙二醛(MDA)含量。实验结束时,测定血浆和肝、肾组织中的上述各项指标及机体总抗氧化力。结果表明,慢性氟中毒大鼠肾脏的脂质过氧化损伤最为明显,其抗氧化酶活力显著下降,脂质过氧化产物血浆MDA含量明显升高。灌服一定剂量的复方当归制剂能缓解氟中毒大鼠牙齿损伤程度,推迟氟斑牙的发生时间,还能明显增强机体总抗氧化力。     

钼对镉胁迫下山羊红细胞膜自由基代谢及脾脏组织病理学的影响

36只体质量约为20kg的山羊被随机分为4个组,每组9只,试验组灌服相同量的CdCl2和不同量的[（NH4）6Mo7·O24·4H2O],对照组灌服对应量去离子水。按每千克体质量计算,低钼组（0.5mg/kg（Cd）＋15mg/kg（Mo））、中钼组（0.5mg/kg（Cd）＋30mg/kg（Mo））、高钼组（0.5mg/kg（Cd）＋45mg/kg（Mo））,每组3个重复。于试验的第0、10、20、30、40、50天每组山羊采血,于试验的第0、25、50天每组山羊取脾脏和肝脏,测定相关指标。结果显示：（1）随着试验时间的延长,各试验组红细胞膜MDA含量呈上升趋势,GSH-Px、GST、SOD活性呈下降趋势;在第50天时,与对照组相比,各试验组红细胞膜MDA含量上升（P〈0.01）,GSH-Px、GST、SOD活性降低（P〈0.01）;（2）与对照组相比,高钼组脾脏的脾小体体积减小,可见散在的含铁血黄素沉积;（3）随着试验时间的延长,各试验组肝脏Bax基因表达量呈上升趋势;在第50天时,与对照组相比,低钼组和高钼组Bax表达量上升（P〈0.05）。结果表明,钼可导致镉胁迫下山羊红细胞膜自由基代谢紊乱,并能损害脾脏的免疫功能并且上调肝Bax基因的表达量,钼和镉体现为协同作用。     

黑果枸杞色素对小鼠的抗脂质过氧化活性的研究

以4—6周龄小鼠为研究对象,通过给小鼠饲喂黑果枸杞色素,测定小鼠红细胞、肝细胞以及全血中SOD活性、谷胱甘肽过氧化物酶活性,并检测黑果枸杞色素对脂质过氧化产物MDA生成的影响和血清MDA及脑内脂褐素含量的变化,观察黑果枸杞色素对小鼠的抗脂质过氧化的活性作用,探讨黑果枸杞色素的抗衰老作用。结果显示,试验组红细胞SOD活性、全血GSH—Px活性及血清GSH—Px／MDA明显高于对照组（P〈0．01）,MDA明显低于对照组（P〈0．05）。说明黑果枸杞色素具有抗氧化活性。     

Amelioration of altered oxidant/antioxidant balance of Indian water buffaloes with subclinical mastitis by vitamins A, D3, E, and H supplementation

The effect of vitamins A, D₃, E, and H supplementation on oxidative stress indices in Indian water buffaloes suffering from subclinical mastitis was investigated. Changes in the total oxidant capacity (TOC), total antioxidant capacity (TAC), nitric oxide (NO), and activities of glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) in milk were evaluated before and after the supplementation of vitamins A, D₃, E, and H. The buffaloes suffering from subclinical mastitis revealed remarkable alterations in the milk oxidants/antioxidants balance shifted towards oxidative status. The buffaloes with subclinical mastitis revealed significantly (P?≤?0.01) higher TOC, NO contents, and CAT activity, while TAC content and GSH-Px activity were significantly (P?≤?0.01) lower in comparison with the healthy controls. However, SOD activity did not show any significant change. Supplementation of vitamins A, D₃, E, and H to these animals revealed significant (P?≤?0.01) reduction in TOC, NO, and CAT, while a significant (P?≤?0.01) increase in TAC and GSH-Px activity was also evident. From the present study, it may be concluded that supplementation of these vitamins can help ameliorate the altered milk oxidants/antioxidants balance towards normalcy and, thus, ensue recovery from subclinical mastitis in the Indian water buffaloes.     

Nursing enhances the negative effect of estrogen on LH release in the cow

Twenty-three crossbred beef cows between 4 and 5 yr of age were assigned at random to one of six treatments: (1) ovariectomized 4 d postpartum (OVX) with early weaning of calves 21 d postpartum (OVX-EW; n = 4), (2) OVX-EW and 17 beta-estradiol implants (OVX-E2-EW; n = 4), (3) OVX and normal nursing by calves throughout the experiment (OVX-NN; n = 3), (4) OVX-NN and 17 beta-estradiol implants (OVX-E2-NN; n = 4), (5) intact cows and early weaning of calves 21 d postpartum (EW), (6) intact cows and normal nursed (NN). Blood was collected at 15-min intervals over a 4-h period once weekly during the 12-wk postpartum period in the OVX cows. Early weaned intact cows exhibited estrus 23 d sooner (P less than .05) than normally nursed cows. A hormone level for each cow at each week was determined from the mean of the 17 samples collected over the 4 h period each week. There were no significant changes due to E2 treatment, for concentrations of LH, FSH or number of pulses during wk 1 through 3. However, during wk 4 through 12 the linear and quadratic contrasts of wk X estrogen X nursing were significant for serum LH, indicating there was no difference between the treatments for EW and NN without E2 but there was a large difference in the presence of E2. During nursing E2 suppressed serum LH below that of nonestrogen-treated cows while after weaning E2 stimulated LH release above that of nonestrogen-treated cows.(ABSTRACT TRUNCATED AT 250 WORDS)