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71.
绵羊卵泡内Ghrelin的免疫组化定位   总被引:1,自引:0,他引:1  
为探索Ghrelin在绵羊各级卵泡的存在和分布,采用免疫组织化学技术研究了Ghrelin多肽在绵羊卵泡中的分布情况。结果表明,初级卵泡、早期生长卵泡和晚期生长卵泡均有Ghrelin表达,卵母细胞呈阳性信号,而在各级卵泡中颗粒细胞Ghrelin呈弱阳性信号。各级卵泡内Ghrelin的表达,提示Ghrelin在卵泡发育过程中可能具有一定作用。  相似文献   
72.
73.
Highly prolific sows often experience peripartum hypophagia, resulting in decreased production rate. Leptin, ghrelin, and resistin are known as feed intake–regulating hormones in many species, but it is yet unknown how feeding strategy and body condition will affect these hormones around parturition in sows. In the present study, a total of 63 sows, parity 2 to 7 were divided over 2 treatment groups which were fed either restricted (RESTRICT) or ad libitum (ADLIB) during the peripartum period (day 106 of gestation until day 7 of lactation). Within each treatment group, sows were assigned to 1 of 3 body condition groups based on back fat thickness at day 106 of gestation: <18 mm (LEAN), between 18 and 22 mm (MODERATE), and >22 mm (FAT). Postprandial blood samples were taken on days 107, 109, and 112 of gestation and on days 1, 3, and 5 of lactation. With RIA, leptin, ghrelin, and resistin of each sample were analyzed. For both leptin and resistin, the hormonal profile gradually increased throughout the peripartum period (P < 0.001), whereas ghrelin peaked on day 109 of gestation compared with day 107 of gestation and day 1 of lactation. Other time points were intermediate between those two (P < 0.001). The peripartum profile of leptin was significantly higher for FAT sows than for the 2 other condition groups. No effect of body condition on ghrelin and resistin concentrations was observed. None of the 3 measured hormones were affected by feeding strategy. In conclusion, during the peripartum period feed intake of sows did not affect leptin, ghrelin, or resistin profiles. Leptin was the only hormone investigated that reflected body condition. Although body condition and late gestation feed intake have been previously described as risk factors for peripartum hypophagia, they did not induce hypophagia in any of the sows or affect the profile of the observed feed intake–regulating hormones during the peripartum period.  相似文献   
74.
Ghrelin, a novel motilin-related endogenous ligand for growth hormone secretagouge receptor, is implicated in various biological functions, including regulation of female reproduction. But the presence of ghrelin and its role in reproductive functions in buffalo, a species with poor reproductive efficiency, is not known. In the present study full-length ghrelin cDNA was isolated from bubaline abomasum, which encodes the entire prepropeptide of 116 amino acids. The deduced amino acid sequence of ghrelin of buffalo showed >95% and 31% identity with that of ruminants (cattle, sheep, and goat) and humans, respectively. Analysis of synonymous and nonsynonymous nucleotide substitutions in the coding region of ghrelin indicated that these sequences of different species have been under purifying selection. The 3995-bp amplicon of ghrelin gene consisting of 4 exons and 3 introns was cloned with genomic DNA from buffalo. Further, ghrelin expression was determined by quantitative real-time PCR, in situ hybridization, and immunohistochemistry in bubaline endometrial tissues at different stages of the estrous cycle and early pregnancy. Our results indicated the persistent expression of ghrelin mRNA and protein in the endometrium during stage I (day 3–5), stage II (day 6–15), and stage III (day 16–21) of the estrous cycle and also during early (∼day 30–40) pregnancy. Immunohistochemistry and quantitative real-time PCR experiments indicated the relatively higher expression of ghrelin in the endometrium during stage II (day 6–15) of the estrous cycle and early pregnancy than during stage I (day 3–5) and stage III (day 16–21) of the estrous cycle, but no statistically significant difference in ghrelin expression was observed among stages. To conclude, the results of the present study indicate the persistent expression of ghrelin in the uterine endometrium throughout the estrous cycle and in early pregnancy which might be helpful in determining its role in buffalo reproduction.  相似文献   
75.
主要对Ghrelin的历史背景、结构与功能、受体的分布、生物学的作用及其前景展望作出详细的论述。  相似文献   
76.
Ghrelin生物学功能的研究进展   总被引:1,自引:0,他引:1  
Ghrelin是一种在大鼠和人胃内新发现的生长激素促分泌素受体(GHS-R)的内源性配基,有28个氨基酸,起促生长激素释放作用。当Ghrelin与位于垂体和下丘脑的GHS-R结合后,产生一系列生物学效应。本文从生长激素释放、机体生长发育、食欲和采食量、能量代谢、胃酸分泌等方面综述了Ghrelin的生物学功能,并初步探讨其在畜牧业上的应用前景。  相似文献   
77.
为了研究Ghrelin在驯鹿生长发育过程中的作用和功能,以驯鹿为研究对象,采用反向嵌套PCR RACE技术原理,根据已知的序列设计1条5'末端磷酸化的特异性反转录引物和2对特异性反向嵌套PCR引物,首先进行反转录(RT),然后将反转录成的cDNA进行环化,最后进行反向嵌套巢式PCR,成功地扩增了驯鹿Ghrelin cDNA 5'末端序列.与锚定PCR相比,反向嵌套PCR法具有特异性强、扩增效率高等优点,是一种非常有效的扩增cDNA 5'末端序列的方法.  相似文献   
78.
猪Ghrelin真核表达质粒的制备及对小鼠生长的影响   总被引:1,自引:0,他引:1  
通过RT-PCR获得猪 Ghrelin基因的cDNA片段,克隆入pcDNA3.1(+)质粒中构建真核表达质粒,将质粒注射到断奶的昆明小鼠的后腿肌肉中,研究Ghrelin真核表达质粒对小鼠生长的影响。结果表明,试验组小鼠在试验第10、20、35 d的增重高于对照组,而在试验结束的第46 d增重无显著差异。说明Ghrelin基因真核表达质粒有促进小鼠生长的作用。  相似文献   
79.
Ghrelin对采食和分泌调节作用的研究进展   总被引:1,自引:0,他引:1  
Ghrelin是从鼠和人的胃中分离得到的一种生长激素释放激素受体天然的内源性配体,它由28个氨基酸残基组成,且氮端第三位丝氨酸发生了辛酰基化,Ghrelin具有广泛的生物学功能,包括调控动物采食、调节生长激素释放、调节胃肠功能及调节能量平衡等,对Ghrelin的研究具有重要的理论意义和广阔的应用前景,文中综述了Ghrelin对采食及对其分泌调节作用的研究进展。  相似文献   
80.
These studies were conducted to determine whether ghrelin, a 28-amino acid peptide produced mainly by the stomach, was involved in tryptophan-mediated appetite stimulation in swine. In experiment 1, 36 crossbred (Long WhitexLarge White) barrows were used in a 2x3 factorial design to determine the effects of food intake (ad libitum versus limit fed) and tryptophan level (0.12%, 0.19% and 0.26%) on growth performance as well as ghrelin expression, plasma insulin, ghrelin and leptin levels. Ad libitum fed pigs gained more weight, but had poorer feed conversion than limit fed pigs. Weight gain, food intake and feed conversion all improved with increased ingestion of dietary tryptophan. Ad libitum feeding increased plasma insulin. Plasma insulin was unaffected by the level of dietary tryptophan. However, plasma leptin was significantly lower in pigs fed 0.19% tryptophan compared to those fed 0.12% tryptophan. Plasma ghrelin levels and ghrelin mRNA level in gastric fundus and duodenun was significantly higher in pigs fed 0.19% and 0.26% tryptophan diet compared with pigs fed 0.12%. In the second experiment, 18 crossbred barrows were divided into three treatments involving oral infusion of saline, tryptophan (40mg/kg BW) or 5-hydroxytryptophan (40mg/kg BW). Plasma ghrelin levels at 20, 40 and 60min after infusion of tryptophan were higher than after saline and 5-hydroxytryptophan infusion, 5-hydroxytryptophan infusion induced lower food intake than saline infusion, and tryptophan infusion increased food intake 2, 8 and 24h after infusion. In conclusion, oral tryptophan ingestion increased ghrelin expression in gastric fundus and plasma ghrelin level.  相似文献   
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