Acute Insulin-induced Hypoglycaemia does not alter IGF-1 and LH Release in Cyclic Mares     

K Deichsel  H-O Hoppen  RM Bruckmaier  G Kolm  C Aurich 《Reproduction in domestic animals》2005,40(2):117-122

Lactation in the mare is associated with changes in the release of metabolic as well as reproductive hormones. Plasma glucose concentration is constantly reduced in lactating compared with non-lactating mares. Several metabolic signals have been proposed to link nutrition and somatic metabolism with reproductive function. The following experiment was performed to study the effect of acute hypoglycaemia on the release of insulin-like growth factor-1 (IGF-1) and luteinizing hormone (LH) in cyclic mares. Different doses of insulin (0.1 and 0.2 IU/kg body weight) were given to induce a decrease in plasma glucose concentration, as existent in lactating mares. All horses treated with insulin developed a hypoglycaemia over a time period of nearly 10 h. The IGF-1 and LH were analysed before and after insulin administration. At no point of time, a significant difference between the two insulin treatments and the control treatment was observed. Therefore, the hypoglycaemic horse is apparently able to provide the brain with sufficient glucose. Short-term hypoglycaemia does not affect the hypothalamo-pituitary-ovarian axis, and concentrations of IGF-1 and LH remained stable during insulin-induced hypoglycaemia. An acute change in plasma glucose concentration is thus not or at least not the only metabolic signal that links nutrition and somatic metabolism with reproductive function in the horse mare.  相似文献   

Blood plasma concentrations of oestradiol-17beta,testosterone and testosterone/oestradiol ratio in dogs with neoplastic and degenerative testicular diseases     

Mischke R  Meurer D  Hoppen HO  Ueberschär S  Hewicker-Trautwein M 《Research in veterinary science》2002,73(3):267-272

Oestradiol-17beta and testosterone blood plasma concentrations were measured in dogs with Leydig-cell tumours (n=20), Sertoli-cell tumours (n=6), seminomas (n=9), unilateral inguinal cryptorchidism (n=7), abdominal cryptorchidism (n=9, one bilateral), degenerate scrotal testicles (n=6, two bilateral), and animals with normal scrotal testicles (n=20). The testosterone/oestradiol ratio (testosterone concentration [ng/mL]x100/oestradiol concentration [pg/mL]) was calculated.A considerably higher oestradiol concentration was found in dogs with Sertoli-cell tumours (29.0, 14.4-48.3 pg/mL; median, minimum-maximum; P=0.0256, Mann-Whitney test) and lower oestradiol levels were found in animals with seminomas (12.0, 3.4-17.6 pg/mL; P=0.0025) compared to the healthy control group (18.0, 8.6-31.5 pg/mL). Testosterone concentration was decreased in dogs with Sertoli-cell tumours (0.08, 0.03-0.77 ng/mL) when compared to the control group (1.95, 0.05-3.70 ng/mL; P=0.0012). Testosterone/oestradiol ratios differed from the control (9.6, 0.58-35.8) only in dogs with Sertoli-cell tumours (0.32, 0.06-2.80; P=0.0005). Clinical signs of feminization were observed in five dogs with Sertoli-cell tumour and one dog with a Leydig-cell tumour, and were more often associated with decreased testosterone/oestradiol ratios than with an increased oestradiol-17beta concentration.  相似文献   

Cyclical endometrial steroid hormone receptor expression and proliferation intensity in the mare     

Aupperle H  Ozgen SSchoon HA  Schoon D  Hoppen HO  Sieme H  Tannapfel A 《Equine veterinary journal》2000,32(3):228-232

The aims of this study were to investigate the steroid hormone receptor expression and the proliferation intensity during the equine endometrial cycle by immunohistological methods, established for routine examination of formalin-fixed, paraplast-embedded specimens. Endometrial biopsy specimens were obtained during one cycle from 7 mares. In comparison with the blood steroid hormone levels the quantity and distribution of oestrogen (ER) and progesterone receptors (PR) and the proliferation marker Ki-67 antigen expression were investigated. Rising 17beta-oestradiol concentrations in preoestrus induce a synchronous expression of ER, PR and Ki-67 antigen in stromal cells. In the early dioestrus 17beta-oestradiol levels decrease and progesterone levels reach their maxima. This correlates with an intense proliferation activity and the highest hormone receptor expression in epithelial cells. In accordance to the morphological features of asynchronous glandular differentiation in fibrotic areas (endometrosis) their epithelial hormone receptor expression is out of phase.  相似文献   

Methanotrophy-driven accumulation of organic carbon in four paddy soils of Bangladesh     

Nasrin SULTANA  Jun ZHAO  Yuanfeng CAI  G. K. M. Mustafizur RAHMAN  Mohammad Saiful ALAM  Mohammad FAHEEM  Adrian HO  Zhongjun JIA 《土壤圈》2022,32(2):348-358

Biological methane oxidation is a crucial process in the global carbon cycle that reduces methane emissions from paddy fields and natural wetlands into the atmosphere.However,soil organic carbon accumulation associated with microbial methane oxidation is poorly understood.Therefore,to investigate methane-derived carbon incorporation into soil organic matter,paddy soils originated from different parent materials(Inceptisol,Entisol,and Alfisol) were collected after rice harvesting from four major rice-producing regions in Bangladesh.Following microcosm incubation with 5%(volume/volume)¹³ CH₄,soil¹³ C-atom abundances significantly increased from background level of 1.08% to 1.88%–2.78%,leading to a net methane-derived accumulation of soil organic carbon ranging from 120 to 307 mg kg^-1.Approximately 23.6%–60.0% of the methane consumed was converted to soil organic carbon during microbial methane oxidation.The phylogeny of¹³ C-labeled pmoA(enconding the alpha subunit of the particulate methane monooxygenase) and 16 S rRNA genes further revealed that canonical α(type II) and γ(type I) Proteobacteria were active methane oxidizers.Members within the Methylobacter-and Methylosarcina-affiliated type Ia lineages dominated active methane-oxidizing communities that were responsible for the majority of methane-derived carbon accumulation in all three paddy soils,while Methylocystis-affiliated type IIa lineage was the key contributor in one paddy soil of Inceptisol origin.These results suggest that methanotroph-mediated synthesis of biomass plays an important role in soil organic matter accumulation.This study thus supports the concept that methanotrophs not only consume the greenhouse gas methane but also serve as a key biotic factor in maintaining soil fertility.  相似文献   

Endogenous opioid peptides in cattle during pregnancy, birth and the newborn period     

I Dobrinski  J E Aurich  E Grunert  H O Hoppen 《DTW. Deutsche tier?rztliche Wochenschrift》1991,98(6):224-226

The concentrations of beta-endorphin and met-enkephalin in plasma were investigated in cows in different stages of gestation, during parturition and in the early postpartum period as well as in their newborn calves. Plasma beta-endorphin concentrations were low in the early stages of pregnancy. In the last month of gestation beta-endorphin levels almost as high as during parturition were found. Therefore in cattle the antepartum increase in plasma beta-endorphin concentration is not linked to the onset of labour. Met-enkephalin levels in plasma of calving cows were higher than those in cows in the last month of gestation. For met-enkephalin a relation to the stress of parturition is more likely than for beta-endorphin. In conjunction with a cesarean section the concentrations of beta-endorphin and met-enkephalin in plasma increased during surgery. This increase is likely to be caused by surgery-related stress. Calves showed highest beta-endorphin concentrations immediately after delivery. One hour post natum beta-endorphin levels were markedly decreased and showed only minor changes thereafter. In calves born at term highest met-enkephalin concentrations were found immediately post natum with levels decreasing continuously over the first two days of life. Preterm calves showed lower met-enkephalin concentrations in plasma than those born at term. During the first hour post natum in preterm animals met-enkephalin levels in plasma even increased. A highly significant correlation existed between met-enkephalin levels and the degree of acidosis in calves. An antagonism between endogenous opioids and catecholamines in newborns is suggested.  相似文献   

第四纪红土发育的水稻土微团聚体特性的初步研究     

何羣  陈家坊 《土壤学报》1964,12(1):55-62

赣中丘陵地区广泛分布着由第四纪红土发育的水稻土,它是重要的产粮地区,也是低产田分布较广的地区。提高低产的红壤性水稻土的肥力,一向是大家所关心的问题,各有关单位做了不少的研究。关于红壤性水稻土的结构特性及胶结物质等曾有研究^[1,9],但对结构形成具有重要意义的微团聚体的特性及其与农业措施的关系,研究较少。土壤微团聚体质和量的研究,可分别土壤肥力的高低,也可阐明輪作、耕作和施肥等措施在培肥中的作用。作者^[4,6]曾进行中性水稻土有机矿质复合体的研究,在此基础上,本文拟就红壤性水稻土中微团聚体¹⁾的特性及其与土壤肥力的关系作一初步了解,为进一步开展这方面的研究提供线索。  相似文献   

Immunohistochemical study of angiogenesis and angiogenic factors in equine granulosa cell tumours     

Müller K  Ellenberger C  Hoppen HO  Schoon HA 《Research in veterinary science》2012,92(3):471-477

The first part of our study (Müller et al., 2009) characterized angiogenesis in the equine cycling ovary through histomorphological and immunohistochemical examinations (vascular endothelial growth factors A and B [VEGF A, VEGF B], vascular endothelial growth factor receptors 1 and 2 [VEGF-R1, VEGF-R2], vascular angiopoietins 1 and 2 [Ang1, Ang2], angiopoietin receptor [Tie2], and von Willebrand Factor). Since angiogenesis plays an important role in development and growth of numerous tumours, the second part of our study involved a similar examination of 70 equine granulosa cell tumours (GCTt). The results of the second study were compared with those of the normal equine ovary. Certain similarities in the expression pattern could be detected between normal, cyclical ovaries (Müller et al., 2009) and GCTt. The immunoreactivity of granulosa cells and Leydig-like cells in GCTt resembles granulosa cells and luteinized thecal cells in periovulatory cycling ovaries. The neoplastic cells support circulation, supply and growth of GCTt by contributing to angiogenesis.  相似文献   

Morphological Examination of the Corpora Lutea from Pregnant Bitches Treated with Different Abortifacient Regimes     

N Martin  T Höftmann  E Politt  HO Hoppen  M Sohr  AR Günzel-Apel  A Einspanier 《Reproduction in domestic animals》2009,44(S2):185-189

Different abortifacient regimes in dogs were analysed for their effect on the pregnancy corpora lutea (CL), namely, prostaglandin F2a analogue cloprostenol (CLO) combined with dopamine agonist cabergoline (CAB), or progesterone (P4) receptor antagonist aglepristone (AGL). Ovaries were collected after 6-10 days of treatment during first trimester. The CL of the control-group showed strong expression of relaxin (RLX), its receptor RXFP1 and enzymes of steroid biosynthesis (HSD) with high peripheral P4-levels. Whereas RXL, RXFP1 and HSD were lowest expressed in the CLO/CAB-group with a massive degeneration of CL and their blood vessels combined with low peripheral P4-level. The AGL-group showed less extensive CL degeneration and more intensive staining of the examined factors than CLO/CAB. In summary, all examined factors are associated with normal luteal function and are useful tools to stage luteolysis. Although both treatments have the same abortive action, their sequence of events on the CL is different.  相似文献   

海南西番莲茎腐病病原的分离与鉴定     

詹儒林  郑服丛  H H HO 《热带作物学报》2003,24(4):39-42

为解决若干病原菌引起的西番莲茎基腐病症状类似,难从症状方面辨别病原菌的问题,采用经典方法即常规鉴定法,对引起海南省琼海市西番莲基腐的病原菌进行鉴定。配制选择性PDA、PDA、V-8、选择性V-84种培养基,对样本中的病原物进行分离、纯化,根据分离菌的各项形态特征描述和分离菌株的主要生长温度测定结果,以及有关文献提供的原理方法进行该分离菌鉴定。结果表明:①分离到1种疫霉菌菌株;②该菌株在选择性PDA、PDA、选择性V-8培养基生长的诸方面特征一样。菌落圆形均一,气生菌丝不丰富。孢子囊形态为侧梨形、柠檬形或椭圆形,基部钝圆,长×宽为24.5～44.3μm×22.8～34.5μm,冷冻后释放游动孢子,未见厚垣孢子。③菌株最低生长温度8～10℃,最适生长温度28℃,最高生长温度36～40℃。④28℃下,分离菌在V-8上日生长量为16.2mm,而在PDA上则为13.7mm。⑤该病原物疫霉菌属于[Phytophthora nicotianae Breda de Haan(parasitica Dastur)]。  相似文献   

台湾中部暖温带阔叶林年轮特征、生长与树龄结构     

詹明勋  何坤益  徐震骐  陈沈佑 《北京林业大学学报》2015,37(3):84-93

台湾目前对于阔叶树种的生长轮少有研究,尤其对于天然阔叶林的生长趋势与模型的相关研究更是缺乏,许多资料仍相当不足,有鉴于此,本研究将针对台湾中部地区的典型暖温带阔叶林进行生长轮的研究与探讨。神木溪保护林于2003年已设置完成18个长期观察的森林动态样区,本研究采用第13~18共6个样区内所有胸径大于6 cm之阔叶树,依据林分特征调查结果,钻取大于6 cm胸径林木,钻取高度约在胸径位置,共取得22科33属39种合计448支树芯。年轮分析运用实体显微镜配合CCD拍摄,目视各树种内年轮的变异,并加以分类,作为年轮目视判视与计数年轮的依据,并用Velmax系统量测年轮宽度,应用树冠级模式(CCM)、定期生长量模式(PAI)及混合模式(Mixed)建立各冠层生长趋势,并解析各树种树龄结构,以提供台湾最大面积、分布最广之楠槠及栎林带林分经营之参考。年轮特征上,属于散孔材树种占79%;半环孔材树种占18%;环孔材树种占3%。生长趋势上,所有树种的平均生长速率统计结果为3.53 mm/a。冠层产生垂直层次分化作用明显,显示出其生长的趋势,上主冠层直径增长情形最快,平均生长率为4.47 mm/a;主冠层其次,平均生长率为2.95 mm/a;底冠层速率最慢,平均生长率为2.92 mm/a。PAI模式显示大部分树种的生长趋势是呈现年轮宽度随树龄增加而增加或线性常数的情形。树龄估算以树冠级模式、PAI模式和混合模式3种模式估算,全部平均年龄分别为55、60、59年。混合模式的利用可以降低单独使用树冠级模式或PAI模式的误差率。树龄结构上,依树冠级模式、PAI模式及混合模式龄级分布结果,本样区充满耐阴性树种前生苗与灌木,逐渐形成典型的复层林。树龄出现2种分群,第1种大多为耐阴性树种的小苗,树木建立时间为20世纪后期;第2种在1900年左右形成了1个独立的单峰。年轮不明显区别造成类型分类的困难,轮宽不规则也无法明确定年,PAI模式需要大量的各龄阶树芯数据建立回归模式,所得到的模型才具有足够之代表性,混合模式虽解决了部分树龄推估的误差,但仍有其他问题,因此日后应更进一步进行探讨与分析,方能对森林生态系之永续经营与发展产生一定程度的帮助。本研究提供暖温带阔叶林林分径向生长与树龄结构信息,以供森林收获采伐和森林永续经营参考。   相似文献