NDV对雏鸵鸟HPA轴的影响

以45日龄雏鸵鸟为试验动物,分正常组和攻毒组,利用RIA技术和TUNEL技术,探讨新城疫病毒（NDV）对雏鸵鸟HPA轴的影响。结果表明,雏鸵鸟感染NDV,HPA轴内细胞凋亡数量在病毒感染期间明显高于对照组,提示NDV能诱导雏鸵鸟HPA轴系统发生细胞凋亡;在病毒接种后1d,肾上腺内可检测到大量凋亡细胞,接种5d后凋亡数量显著增加（P〈0.05）,之后凋亡呈下降趋势,肾上腺内细胞凋亡的动态变化反映了雏鸵鸟HPA轴对ND病变的适应和调节。雏鸵鸟感染NDV,血清ACTH水平于NDV接种后1d开始上升,至5d达到峰值（P〈0.01）,之后有所下降,渐趋于正常;血清Cor水平于病毒接种后1d开始下降,至7d有所回升,9d渐趋于正常水平,表明NDV接种后雏鸵鸟血清ACTH和Cor水平的变化与其HPA轴功能的损伤及恢复密切相关。     

Regulation of pituitary somatotroph differentiation by hormones of peripheral endocrine glands

Anterior pituitary somatotroph differentiation occurs during chick embryonic and rat fetal development. A number of findings support the hypothesis that differentiation of these growth hormone (GH) producing cells in the chick and the rat is regulated by adrenal glucocorticoids and thyroid hormones. Somatotroph differentiation can be induced in cultures of chick embryonic and rat fetal pituitary cells with adrenal glucocorticoids and this effect can be modulated by concomitant treatment with thyroid hormones. Plasma levels of thyroid hormones, corticosterone and adrenocorticotropic hormone increase during development, consistent with the ontogeny of somatotrophs. Treatment of chick embryos or rat fetuses with glucocorticoids in vivo induces premature somatotroph differentiation, indicating that the adrenal gland, and ultimately anterior pituitary corticotrophs, may function to regulate pituitary GH cell differentiation during development. Administration of thyroid hormones in vivo also increases somatotrophs prematurely, and administration of the thyroid hormone synthesis inhibitor methimazole inhibits somatotroph differentiation in vivo, suggesting that endogenous thyroid hormone synthesis contributes to normal somatotroph differentiation. Our working model for the regulation of somatotroph differentiation during normal development includes modulation by elements of the hypothalamo-pituitary-adrenal and hypothalamo-pituitary-thyroid axes. Additional research is reviewed defining the mechanism of action for these peripheral hormones in induction of pituitary GH gene expression during development.     

脂多糖刺激对断奶仔猪下丘脑-垂体-肾上腺轴PPARγ表达的影响

研究脂多糖(LPS)对断奶仔猪下丘脑-垂体-肾上腺(HPA)轴过氧化物酶体增殖物活化受体γ(PPARγ)表达的影响。对照组注射生理盐水,试验组注射LPS。注射后1.5 h和3 h采血,3 h采血后屠宰。结果表明:LPS刺激后1.5 h,中性粒细胞含量及其比例显著下降(P<0.05);LPS刺激后3 h,白细胞、淋巴细胞、中性粒细胞含量显著下降(P<0.05)。LPS刺激后1.5 h,血浆肿瘤坏死因子(TNF)-α、皮质醇和促肾上腺皮质激素释放素激素(CRH)含量显著上升(P<0.05);LPS刺激后3 h,血浆TNF-α、皮质醇和促肾上腺皮质激素(ACTH)含量显著上升(P<0.05);LPS刺激导致下丘脑、腺垂体、肾上腺皮质和髓质中PPARγ阳性细胞百分率显著升高(P<0.05)。这表明LPS导致免疫应激,激活HPA轴,诱导HPA轴PPARγ的表达。     

鸡常见胚胎病及其防治

鸡胚胎病是指鸡在胚胎发育过程中所出现的疾病。有效控制鸡的胚胎病,对提高受精率、出雏率、健雏率及提高鸡的生产力和养殖效益都有十分重要的意义。对鸡常见胚胎疾病的病因、疾病类型以及防治措施进行了综述。     

鸡胚器官左右不对称性发育的研究进展

鸡的体内器官表现出明显的左右不对称性,这些不对称性的确立发生在胚胎发育的早期,并且要求多种机制共同筹划和有序进行。对于从亨氏节(Hensen’s node)到机体原基的左右信息传递的基因网络已经有了较清楚的阐述。有助于我们对这种机制的理解。以鸡胚为模式动物进行不对称性发生和发育的研究具有多种优点,文章以鸡胚为发育模式,对器官不对称性发育的分子机理,研究方法和未来的研究趋势进行了较为详细的介绍和论述,以期丰富我们对器官不对称发育的理解。     

Hyperadrenocorticism in cats: seven cases (1978-1987)

Hyperadrenocorticism was diagnosed in 7 cats with concurrent diabetes mellitus. Four cats had pituitary adenoma with bilateral adrenocortical hyperplasia, 1 cat had pituitary carcinoma with bilateral adrenocortical hyperplasia, 1 cat had adrenocortical carcinoma, and 1 cat had adrenocortical adenoma of the left adrenal gland. One year later, adrenocortical adenoma involving the right adrenal gland also was diagnosed in this cat. Clinical signs included polyuria and polydipsia (n = 7), development of pot-bellied appearance (n = 5), dermatologic alterations (n = 5), lethargy (n = 3), weight loss (n = 3), dyspnea/panting (n = 2), and recurrent bacterial infections (n = 2). In 6 cats, the diagnosis of hyperadrenocorticism was established before death on the basis of results of the ACTH stimulation test (n = 3) and the dexamethasone screening test (n = 5). Pituitary-dependent hyperadrenocorticism was differentiated from adrenocortical neoplasia on the basis of results of the dexamethasone suppression test (n = 4), endogenous ACTH concentration (n = 3), results of abdominal radiography and ultrasonography (n = 3), and exploratory celiotomy (n = 1). Four cats died or were euthanatized without treatment attempts. Treatment with mitotane followed by 60Co teletherapy was ineffective in one cat with pituitary adenoma. One cat with pituitary carcinoma died one week after bilateral adrenalectomy. Bilateral adrenocortical adenomas were removed surgically in the affected cat.     

Chicken folliculo-stellate cells express thyrotropin receptor mRNA

We investigated the presence of thyrotropin receptor (TSHR) mRNA in chicken pituitary and brain, and quantified the changes in its expression during the last week of embryonic development. We found that in the pituitary gland, TSHR mRNA co-localizes with folliculo-stellate cells but not with thyrotropic cells, suggesting the existence of a paracrine ultra-short thyrotropin feedback loop. TSHR mRNA was also present throughout the diencephalon and various other brain regions, which implies a more general function for thyrotropin in the avian brain. During late embryogenesis, when the activity of the hypothalamo-pituitary-thyroidal axis increases markedly, a significant rise in TSHR mRNA expression was observed in pituitary, which may signify an important change in pituitary ultra-short thyrotropin feedback regulation around the period of hatching.     

Prenatal development of the adrenal gland in the one-humped camel (Camelus dromedarius)

With 14 figures and 3 tables SUMMARY: Each adrenal gland consisted of cortex and medulla that developed from different embryological origins and presented different cellular organization. One hundred male or female camel embryos or fetuses with crown vertebral rump lengths (CVRL) that ranged from 0.8 to 117 cm were examined. The adrenal cortex, which is derived from intermediate mesoderm, was first observed in the 0.8-cm CVRL camel embryo. The adrenal cortex initially was combined with the gonad as a thickened region of proliferating cells derived from splanchnic intermediate mesoderm. Adrenocortical tissue was first separated from the gonadal tissue in the 2-cm CVRL camel fetus and was observed as a separate dorso-medial mass of cells. At 2.5-cm CVRL, the adrenocortical tissue was surrounded by a capsule of undifferentiated mesenchymal cells, except at its proximal pole, where an invagination was located through which chromaffinoblast cells entered the cortex. The chromaffinoblast cells migrated from the neural crest to form the medulla of the developing adrenal gland. In the 3.5-cm CVRL camel fetus, the adrenocortical cells differentiated into two layers: the inner fetal cortex and the outer definitive cortex. As development proceeded, the fetal cortex degenerated and the definitive cortex formed the zona glomerulosa and zona fasciculata. The zona reticularis did not form until the end of gestation. During prenatal life, the adrenal medulla was much thicker than the cortex.     

郁金散对大肠湿热证大鼠HPA轴的影响机制

基于分子对接并辅以生物学验证探讨郁金散治疗大肠湿热证HPA轴损伤的机制。采用高效液相色谱法(High Performance Liquid Chromatography,HPLC)检测郁金散的主要活性成份,用分子对接观察其活性成分与HPA轴相关激素、蛋白之间的结合力,通过网络药理学分析构建药物靶标网络,预测郁金散活性成分作用的主要靶标,并建立大肠湿热证大鼠模型,进行生物学验证。计算各组大鼠肾上腺指数,观察肾上腺组织变化特征,检测关键靶标及其下游激素的表达量。分子对接与网络分析可以推测CRH可能是调控HPA轴亢进的潜在蛋白,盐酸小檗碱、没食子酸、大黄素可能是郁金散调节HPA轴亢进的活性成分。生物学验证实验结果表明,与空白对照组相比,模型组和自愈组大鼠肾上腺指数及血清中CRH、ACTH、CORT的含量显著或极显著升高(P<0.05或P<0.01),模型组大鼠肾上腺出现一定的病理变化。经郁金散治疗后,以上各指标及病理变化均有所改善,其中以郁金散高剂量组治疗效果最佳,验证了分子对接的部分预测结果。研究证实郁金散可能是通过下调CRH的水平调节大肠湿热证大鼠HPA轴功能亢进,为进一步开展郁金散治疗HPA轴亢进的机制研究提供了新思路和新方法。     

Effects of dermal dexamethasone application on ACTH and both basal and ACTH-stimulated cortisol concentration in normal horses

There are no data available regarding the systemic (adverse) effects which might be induced by topical/dermal glucocorticoids (GCs) application in the horse. Besides their widespread use for the treatment of a variety of peripheral inflammatory disorders such as atopic dermatitis, eczemas or arthritis in the horse, their surreptitious application has become a concern in doping cases in competition/performance horses. Assessing both basal and ACTH‐stimulated plasma cortisol as well as basal ACTH concentrations following application of dexamethsone‐containing dermal ointment is necessary to determine influences on hypothalamus‐pituitary‐adrenal (HPA) axis. Ten clinically healthy adult standardbred horses (6 mares, 4 geldings) were rubbed twice daily each with 50 g dexamethasone‐containing ointment on a defined skin area (30 × 50 cm) for 10 days. RIA and chemiluminescent enzyme immuno‐metric assay were used to determine resting and ACTH‐stimulated plasma cortisol and basal ACTH concentrations, respectively. HPA feedback sensitivity and adrenal function were measured by a standard ACTH stimulation test. Dermal dexamethasone suppressed significantly the resting plasma cortisol level (to 75–98%) below baseline (P < 0.001) within the first 2 days and decreased further until day 10. ACTH stimulation test showed a markedly reduced rise in plasma cortisol concentrations (P < 0.001 vs. baseline). Plasma ACTH level decreased also during topical dexamethasone application. The number of total lymphocytes and eosinophil granulocytes was reduced, whereas the number of neutrophils increased. No significant change of serum biochemical parameters was noted. Dermal dexamethasone application has the potential to cause an almost complete and transient HPA axis suppression and altered leukocyte distribution in normal horses. The effects on HPA axis function should be considered in relation to the inability of animals to resist stress situations. The data further implicate that percutaneously absorbed dexamethasone (GCs) may cause systemic effects relevant to ‘doping’.     

Pituitary and adrenocortical responses to corticotropin-releasing factor in pigs

A study was conducted to determine whether differences in adrenocortical response to exogenous adrenocorticotrophin (ACTH) were an accurate reflection of an animal's perception of and response to stressful stimuli, or whether the pituitary gland might modulate adrenocortical responsiveness. Sixteen Large White x Landrace female pigs, of which 8 had high adrenocortical response to ACTH and the other 8 had low response, were administered IV a bolus of synthetic human corticotropin-releasing factor (hCRF) at dose rates ranging from 0.002 to 2 micrograms/kg of body weight. Blood samples were collected at known times for up to 2 hours after administration of hCRF. Plasma ACTH and cortisol concentrations were measured by radioimmunoassay. Results indicate that hCRF stimulated the pituitary gland of high- and low-responding pigs to secrete ACTH, which in turn stimulated the adrenal cortex to secrete cortisol. Plasma ACTH concentration, before or after hCRF administration, was not significantly different between the high and low responders. However, high-responding pigs had higher cortisol concentration after hCRF administration than did low-responding pigs. Thus, the differences in adrenocortical response to ACTH between the 2 groups of pigs were not attenuated by variation in pituitary response. It is concluded that adrenocortical responsiveness to ACTH is an accurate indicator of the perception of and the response to stress.     

Serum Inhibin Concentration in Dogs with Adrenal Gland Disease and in Healthy Dogs

Background

Studies in humans identified the synthesis and secretion of inhibin from adrenocortical tumors, but not pheochromocytoma (PHEO). Inhibin has not been examined in dogs as a serum biomarker for adrenal gland tumors.

Objective

To determine serum inhibin concentration in dogs with adrenal gland disease and in healthy dogs.

Animals

Forty‐eight neutered dogs with adrenal disease including pituitary‐dependent hyperadrenocorticism (PDH, 17), adrenocortical tumor (18), and PHEO (13), and 41 healthy intact or neutered dogs.

Methods

Prospective observational study. Dogs were diagnosed with PDH, adrenocortical tumor (hyperadrenocorticism or noncortisol secreting), or PHEO based on clinical signs, endocrine function tests, abdominal ultrasound examination, and histopathology. Inhibin concentration was measured by radioimmunoassay in serum before and after ACTH stimulation, and before and after treatment.

Results

In neutered dogs, median inhibin concentration was significantly higher in dogs with adrenocortical tumors (0.82 ng/mL) and PDH (0.16 ng/mL) than in dogs with PHEO and healthy dogs (both undetectable). Median inhibin concentration was significantly higher in dogs with adrenocortical tumors than in those with PDH and decreased after adrenalectomy. Median inhibin concentration was significantly higher in intact than in neutered healthy dogs and was similar in pre‐ and post‐ACTH stimulation. Sensitivity, specificity, and accuracy of serum inhibin concentration for identifying an adrenal tumor as a PHEO were 100, 88.9, and 93.6%, respectively.

Conclusions and Clinical Importance

Adrenocortical tumors and PDH but not PHEOs are associated with increased serum inhibin concentration; undetectable inhibin is highly supportive of PHEO in neutered dogs with adrenal tumors.     

鸡胚胎干细胞的分离及其嵌合体制备条件探索

分离培养鸡胚胎干细胞(ESCs),体外培养传代后,进行碱性磷酸酶活性检测和SSEA-1染色鉴定;并用线性化的质粒pEGFP-N1转染鸡ESCs。受体种蛋经赤道面开窗后,将经转染的ESCs注射到受体鸡胚胚下腔,以便制作嵌合体鸡;对获得的嵌合体鸡分别提取血液和组织DNA后进行PCR检测。结果表明:5只存活的的嵌合体鸡血液中没有发生EGFP基因嵌合,但有4只嵌合体鸡的部分器官表达了EGFP基因,其中有2只鸡的性腺发生嵌合,表明利用赤道面开窗后对受体鸡进行胚下腔显微注射可以生产嵌合体鸡。     

The immediate effects of weaning stress on the hypothalamus‐pituitary‐adrenal alteration of newly weaned piglets

This study was conducted to examine the effects of weaning stress on gene expression of specific markers in hypothalamus‐pituitary‐adrenal (HPA) axis and neuronal activity in the newly weaned piglets. Twelve 28‐days‐old, newly weaned crossbred (Landrace × Yorkshire × Duroc) male piglets from 6 l (2 piglets/l) were randomly categorized into two groups: (a) weaning stress: piglets were separated from their dams, relocated and mixed with the unacquainted domestic piglets for 2 hr (stress, n = 6); (b) no‐stress: piglets stayed with their dams in the farrowing house (NS; n = 6). After weaning stress, all piglets were electrically euthanized and the blood samples/HPA tissues were collected for subsequent analysis, including plasma cortisol and mRNA expression of c‐fos, c‐jun, corticotropin‐releasing hormone (CRH), CRH receptor 1 (CRHR‐1) and adrenocorticotropin hormone receptor (MC2R). Results: Weaning stress significantly (p < 0.05) increased the plasma cortisol level and suppressed the expression of c‐fos and CRH in hypothalamus. In addition, weaning stress enhanced the mRNA abundance of c‐jun and CRHR‐1 in the pituitary gland. No significant differences in the gene expression of MC2R and CRHR‐1 were observed in the adrenal gland between treatment groups. Taken together, HPA involved in weaning stress and CRHR‐1 and c‐jun could be potential markers to evaluate the activation of HPA axis.     

Multiple endocrine neoplasias in a dog: Corticotrophic tumour,bilateral adrenocortical tumours,and pheochromocytoma

Summary

In a 10‐year‐old ovariohysterectomized standard Schnauzer, the finding of dexamethasone‐resistant hypersecretion of cortisol, the results of computed tomography, and elevated plasma concentrations of ACTH suggested the presence of both adrenocortical tumour and pituitary‐dependent hyperadrenocorticism. The dog made an uneventful recovery after bilateral adrenalectomy and remained in good health for 31/2 years with substitution for the induced hypoadrenocorticism. Then the enlarged pituitary caused neurological signs and eventually euthanasia was performed. The surgically excised right adrenal contained a well‐circumscribed tumour of differentiated adrenocortical tissue and in the left adrenal there were two adrenocortical tumours and a pheochromocytoma. The unaffected parts of the adrenal cortices were well developed and without regressive transformation. At necropsy there were no metastatic lesions. The cells of the pituitary tumour were immunopositive for ACTH and had characteristics of malignancy.

The present combination of corticotrophic tumour, adrenocortical tumours, and pheochromocytoma may be called ‘multiple endocrine neoplasia’ (MEN), but does not correspond to the inherited combinations of diseases known in humans as the MEN‐1 and the MEN‐2 syndromes. It is suggested that the co‐existence of hyperadrenocorticism and pheochromocytoma may be related to the vascular supply of the adrenals. Some chromaffin cells of the adrenal medulla are directly exposed to cortical venous blood, and intra‐adrenal cortisol is known to stimulate catecholamine synthesis and may promote adrenal medullary hyperplasia or neoplasia.     

慢性冷热应激对放牧西门塔尔牛抗氧化功能及HPA轴、SAM轴激素分泌的影响

为研究慢性冷热应激对放牧条件下西门塔尔牛生理指标、抗氧化功能及下丘脑-垂体-肾上腺皮质轴(HPA)、交感-肾上腺-髓质轴(SAM)激素分泌的影响,选取内蒙古锡林郭勒盟苏尼特左旗某家庭牧场体质量相近、体况健康的西门塔尔牛20头,试验期间测定试验牛生理指标,于试验期最后一天清晨进行颈静脉采血并制备血清,采用ELISA方法检...     

去势对白来航母鸡垂体和肾上腺的影响

垂体和肾上腺在摘除卵巢的雌性动物性激素合成过程中起到重要作用。为研究去势对白来航母鸡垂体和肾上腺的影响,实验对6只9周龄白来航母鸡进行卵巢摘除手术,饲养至97周龄时,检测去势白来航母鸡与同周龄未去势母鸡的血清性激素水平、冠高和距长,比较分析垂体重、肾上腺重差异,并检测垂体发育相关基因GREB1的表达量。结果显示:去势母鸡雌二醇浓度(P<0.05)、肾上腺重量(P<0.01)以及GREB1相对表达量(P<0.05)低于未去势母鸡;冠高、距长和垂体重量高于未去势母鸡(P<0.05)。可见,摘除母鸡卵巢可抑制肾上腺发育,促进垂体发育。     

Hypothalamo-pituitary-adrenal gland axis in mice inhaling toluene prior to low-level long-term exposure to formaldehyde

We studied the change in the hypothalamo-pituitary-adrenal gland (HPA) axis upon adding prior toluene inhalation to our previous formaldehyde inhalation experiments to determine whether short term exposure to relatively high levels of toluene triggers multiple chemical sensitivity (MCS). Data come from immunocytochemical, morphometrical and RT-PCR measurements. Four groups of adult female mice were exposed to differing concentrations (0, 80, 400, and 2,000 ppb) of formaldehyde for 16 hr/day, 5 days/week for twelve weeks, after the mice were exposed intranasally to 500 ppm toluene per mouse for 6 hr/day, for 3 days. We found that the number of corticotropin releasing hormone (CRH)-immunoreactive (ir) neurons was up-regulated according to the amount of formaldehyde as well as inhalation of formaldehyde alone in our previous experiment. The proportion of adrenocorticotropin hormone (ACTH)-ir cells increased according to the formaldehyde concentration, though there was no significant difference between the 400 and 2,000 groups. The number of ACTH-ir cells was higher in the 400 group than in the other groups (0, 80, and 2,000). Expression of ACTH-mRNA was also up-regulated according to the quantity of formaldehyde. The sinusoid in the anterior pituitary showed more dilatation in the 400 and 2,000 groups than in the control group, especially in the 2,000 group. We propose that exposure to toluene prior to inhalation of formaldehyde has no effect on the HPA axis and as a trigger of MCS, although greater sinusoid dilatation was found in the anterior pituitary gland at higher concentrations of formaldehyde.     

Association study of molecular polymorphisms in candidate genes related to stress responses with production and meat quality traits in pigs

The hypothalamic-pituitary-adrenal (HPA) axis exerts a large range of effects on metabolism, the immune system, inflammatory processes, and brain functions. Together with the sympathetic nervous system, it is also the most important stress-responsive neuroendocrine system. Both systems influence production traits, carcass composition, and meat quality. The HPA axis may be a critical target for genetic selection of more robust animals. Indeed, numerous studies in various species have demonstrated the importance of genetic factors in shaping the individual HPA axis phenotype, and genetic polymorphism can be found at each level of the axis, including hormone production by the adrenal cortices under stimulation by adrenocorticotropic hormone (ACTH), hormone bioavailability, or receptor and postreceptor mechanisms. The aim of the present experiment was to extend these findings to the brain neurochemical systems involved in stress responses. To this end, a number of candidate genes were sequenced for molecular polymorphisms and their association was studied with stress neuroendocrine and production traits in a genetically diverse population consisting of 100 female pigs from an advanced intercross (F10-F12) between 2 highly divergent breeds, Large White (LW) and Meishan (MS). The LW breed has a high production potential for lean meat and a low HPA axis activity, and the MS breed has low growth rate, fat carcasses—but large litters of highly viable piglets—and a high HPA axis activity. Candidate genes were chosen in the catecholaminergic and serotonergic pathways, in the pituitary control of cortisol production, among genes previously demonstrated to be differentially expressed in ACTH-stimulated adrenal glands from LW and MS pigs, and in cortisol receptors. Sixty new polymorphisms were found. The association study with carcass and meat quality traits and with endocrine traits showed a number of significant results, such as monoamine oxidase (MAOA) polymorphisms with growth rate (P = 0.01); lean content and intramuscular fat (P < 0.01), which are the most important traits for carcass value; dopamine receptor D3 (DRD3) with carcass composition (P < 0.05); and vasopressin receptor 1B (AVPR1B) with meat quality traits (P ≤ 0.05). The effect of these polymorphisms on neuroendocrine parameters (eg DRD3 and HPA axis or AVPR1B and catecholamines) indicates information regarding their biological mechanism of action.