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1.
抑制素免疫与超数排卵   总被引:2,自引:0,他引:2  
寻找一种简单的繁殖技术以提高排卵率或用作超数排卵是长期以来的目标。虽然利用促性腺激素的超排技术已成为获得可移植胚胎的有效手段,但仍有许多问题尚未解决。最突出的问题是:外源促性腺激素处理后个体差异较大,甚至出现PMSG处理后大卵泡不排卵的报道[1]。近年来国内外学者发现抑制素对垂体FSH具有负反馈调节作用,认为内源性抑制素的抑制可能缓解这些问题,因而在促进动物多产和超排的研究中开始关注抑制素及其免疫中和技术[2,3,4]。1 抑制素特性抑制素(Inhibin,INH)是一种由动物性腺分泌的糖蛋白激素,是由α、β两个亚…  相似文献   

2.
抑制素免疫对羊生殖的影响   总被引:4,自引:0,他引:4  
抑制素是一种主要由动物性腺(睾丸的支持细胞和卵巢的颗粒细胞)分泌的一种异二聚体糖蛋白激素,由两个二硫键连接两个不同的亚单位(α和β)构成。抑制素对垂体FSH的分泌和/或合成具有选择性地抑制作用。抑制素免疫中和技术能特异性地刺激FSH分泌,进而促进配子生成,提高动物繁殖力。西方把抑制素免疫对羊排卵率、产羔数、初情期、超数排卵和公羊繁殖性能的影响作一综述。  相似文献   

3.
抑制素是二聚体糖蛋白激素,是机体分泌的一种能够调节促性腺激素分泌的活性物质,能够提高家畜的排卵率和繁殖力。抑制素抗原免疫可以提前动物发情,有效提高雌性动物的排卵率,对雄性动物生殖功能也起到重要的作用,因而研究抑制素对动物繁殖的影响,对于提高动物的生殖潜力有着很好的应用前景。  相似文献   

4.
抑制素是由动物性腺分泌的异二聚体蛋白激素,它通过选择性抑制垂体促性腺激素(主要是FSH)的分泌,进而影响动物的生殖活动。而利用抑制素对动物主动或被动免疫,可增加排卵率,提高繁殖力的独特功能越来越受到人们的重视。本文就近年来有关抑制素免疫对动物生殖功能影响的研究作一综述。  相似文献   

5.
抑制素是机体分泌的一种能够调节促性腺激素分泌的活性物质.通过抑制素免疫中和技术能够解除抑制素对FSH分泌的抑制作用,从而促进排卵.本文对抑制素及其免疫机理、免疫方法、免疫对动物繁殖性能影响的研究进展作一综述.  相似文献   

6.
抑制素免疫的研制进展   总被引:1,自引:0,他引:1  
抑制素是机体内分泌的一种能够调节促性腺激素分泌的活性物质,通过抑制素免疫中和技术能够解除抑制素对FSH分泌的抑制作用,从而促进排卵,本文对抑制素及其免疫机理,免疫方法,免疫对动物繁殖性能影响的研究进展作一综述。  相似文献   

7.
卵泡抑制素主动和被动免疫及其基因免疫研究进展   总被引:4,自引:0,他引:4  
抑制素是由动物卵巢颗粒细胞或睾丸间质细胞分泌的糖蛋白激素,对垂体FSH的分泌具有抑制作用。用抑制素或其片断主动或被动免疫可以提高家畜的排卵率和产仔籽;用抑制素基因免疫可望得到类似效果。本文通过分析抑制系的理化特性。生物学作用及作用机制,主动和被动免疫对家畜繁殖力的影响,阐述了抑制素基因免疫的原理与方法及应用前景。  相似文献   

8.
母猪性发育及性周期过程中外周血浆LH、FSH的分泌模式   总被引:2,自引:0,他引:2  
母猪的性发育和性周期受到下丘脑-垂体-卵巢轴的调节,虽然下丘脑起着主宰作用,却受到主要由卵巢和腺垂体分泌的生殖激素的影响。LH、FSH是由腺垂体分泌的促性腺激素,在调节性发育和性周期的过程中起着重要的作用。自从激素的放免方法建立以来,已能观察到性发育和性周期中促性腺激素的动态变化。1 性发育过程中LH、FSH的分泌胎儿是非常活跃的激素生产单位,胎儿内分泌活动对分娩产生决定性的作用。妊娠晚期胎儿体内合成大量促性腺激素,并且带到出生后,因而仔猪刚出生后血浆中LH、FSH浓度很高。Ponzilius等…  相似文献   

9.
抑制素是机体分泌的一种能够调节促性腺激素分泌的活性物质,它能够提高家畜的排卵率和繁殖力.作者对抑制素及其免疫机理、免疫方法和免疫对家畜繁殖性能影响的研究进展进行了概述.  相似文献   

10.
综述了太湖猪高繁殖力内分泌学机制的研究进展,结果表明太湖猪促黄体素(LH)促卵泡素(FSH)的高含量以及FSH分泌对抑制素的抑制效应较不敏感,尤其是FSH的高含量,很可能是太湖猪高排卵率的重要因素之一。  相似文献   

11.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

12.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

13.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

14.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

15.
16.
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.  相似文献   

17.
Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein  相似文献   

18.
A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

19.
Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L3) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L3 developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.  相似文献   

20.
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