Similarities and differences in oxynticopeptic cell ultrastructure of one marine teleost, Gadus morhua and one freshwater teleost, Oncorhynchus mykiss, during basal and histamine-stimulated phases of acid secretion

Oxynticopeptic cells (OC) from rainbow trout, Oncorhynchus mykiss, and Atlantic cod, Gadus morhua, were studied during basal acid secretion and during stimulation with histamine. An in vitro method for measuring acid secretion from isolated stomac a was used. The OC ultrastructure was studied using electron microscopy. During basal acid secretion, the OC had short apical microvilli, an extensive tubulovesicular network, large electron-dense vesicles and many mitochondria. Stimulation of acid s tion with histamine and ultrastructural changes in the OC occurred simultaneously. The acid stimulation promoted large increases in the length of microvilli, a decrease in the size of the tubulovesicular network and an increase in the diameter of the ndular lumen in cod. Large vacuoles were found to characterize the histamine-stimulated OC. These were located close to the apical membrane and sometimes opened into the lumen. During stimulation, electron-dense vesicles were often observed close to apical membrane and the large vacuoles. Sometimes these vesicles were observed inside the glandular lumen and/or the large vacuoles. It is concluded that the ultrastructure of the OC in the saltwater cod and the freshwater trout show similar characte ics as OC in other animal groups both during basal and high rates of acid secretion. In addition, vacuoles were found in both species OC during basal rates of acid secretion and they significantly increased in size during high rates of acid secretion propose that the OC vacuole have a part in the osmoregulation, since the increase was tenfold in cod but less then one-fold in trout, this difference was statistically significant.     

大弹涂鱼TLR基因分子进化研究及其在鳗弧菌胁迫后的表达分析

大弹涂鱼(Boleophthalmus pectinirostris)是一种生活在潮间带的淤泥滩和红树林等两栖环境中的鱼类,其免疫系统面临比水生生活更大的选择压力。Toll样受体基因(简称TLR)是重要的先天免疫成员,一直是鱼类分子免疫学的研究热点之一。为了探究大弹涂鱼TLR基因是否因为其独特的生活环境而产生适应性进化以及其TLR基因在受到细菌攻击后的免疫应答模式,本研究从大弹涂鱼皮肤转录组中获得了TLR5, TLR8和TLR9完整序列以及TLR3和TLR7部分序列,采用分子生物信息学对大弹涂鱼TLR5, TLR8和TLR9基因序列以及氨基酸序列进行了分析,并根据所构建的系统发育树对5个TLR基因进行了分子进化分析,采用荧光定量PCR方法对大弹涂鱼5个TLR基因的组织表达分布和鳗弧菌攻击后5个TLR基因的免疫应答模式开展了研究。结果显示, TLR5基因全长3071 bp,包括长度为2646 bp的编码区,共编码882个氨基酸;TLR8基因全长3175 bp,包括长度为3033 bp的编码区,共编码1011个氨基酸;TLR9基因全长3398 bp,编码区长度为3093 bp,共编码1031个氨基酸。大弹涂鱼3个TLR基因与其他物种的TLR基因结构相似,具有高度保守性。位点模型结果表明,鱼类TLR3, TLR5和TLR8是高度保守的,而TLR7和TLR9在长期进化过程中产生了适应性进化;而进化枝-位点模型结果表明,为了适应更加复杂多变的两栖环境,大弹涂鱼TLR9基因可能产生了适应性进化。大弹涂鱼5个TLR基因在8个健康组织(肠,眼,肾,肝,脑,肌肉,脾和皮肤)中均有表达,在肝脏和脾脏中的表达量较高。在受到鳗弧菌(Vibrio anguillarum)攻击后的免疫表达模式表明了大弹涂鱼5个TLR基因在应对细菌入侵时起到了重要作用。     

古梅灵芝和梅子精抗过敏性作用的研究

抑制组胺游离和肠管收缩等过敏反应的研究表明,对于由Ｃｏｍｐｏｕｎｄ４８／８０或ＩｇＥ抗血清反应引起的老鼠腹腔细胞中组胺的游离及外源组胺引起的土拨鼠肠管的收缩,古梅灵芝和梅子精均有明显的抑制作用．     

鸡球虫病红细胞免疫功能检测

用柔嫩艾美耳球虫人工感染８日龄雏鸡４０只,感染７日后测定红细胞Ｃ３６花环率和ＩＣ花环率,与健康对照组比,Ｃ３６花环率显著降低（Ｐ〈０．０１）,ＩＣ花环率显著升高（Ｐ〈０．０１）,表明鸡球虫病可引起红细胞免疫功能发生改变。     

α-芋螺毒素与烟碱型乙酰胆碱受体作用的药理学

芋螺毒素(CTX)来源于芋螺毒管分泌的毒液,是一类分子质量小、结构新颖、作用靶点广泛且特异性高的活性多肽,具有开发成为药物或药物先导化合物的价值。芋螺毒素按其作用靶点不同等特点可以分为多个家族,其中α-芋螺毒素家族(α-CTXs)的半胱氨酸模式为:CC-C-C。根据α-CTXs半胱氨酸残基间的氨基酸数目进一步分为不同的亚家族。α-CTXs是肌肉或神经型烟碱乙酰胆碱受体的选择性拮抗剂,具有重要临床意义的乙酰胆碱受体(nAChRs)与神经痛、帕金森病、痴呆、学习记忆障碍以及小细胞肺癌等多种疾病的发病、诊断和治疗密切相关。笔者详述了α-芋螺毒素与烟碱型乙酰胆碱受体的结构、分类及其相互间的作用关系,旨在为该类药物的开发利用提供参考依据。     

柱前衍生—高效液相色谱法测定鱼粉中组胺的含量

为了建立鱼粉中组胺药物残留量测定的柱前衍生-高效液相色谱法,将样品匀浆后经高氯酸水溶液超声提取,提取液经丹酰氯衍生后,采用紫外检测器在254 nm处对组胺酮进行检测。结果表明,组胺分离效果好,检出限（LOD）为25.0 mg/kg,定量限（LOQ）为50.0μg/kg,相对标准偏差为2.11%~4.76%（n=6）,加标回收率达到79.5%~90.1%。该方法具有比较高的重现性和选择性,适用于鱼粉中组胺的残留测定。     

Dopamine functions as a growth hormone-releasing factor in the goldfish,Carassius auratus

In vivo and in vitro approaches have been used to examine the role of dopamine (DA) as a growth hormone (GH)-releasing factor in the goldfish. DA stimulated GH release from perifused pituitary fragments of goldfish in a dose-dependent manner. The GH-releasing effect of DA was seasonal, being the highest in sexually regressed fish, intermediate in recrudescent fish, and the lowest in sexually mature (prespawning) fish. The GH response to DA was blocked by the D1 antagonist (+)SCH23390, confirming the involvement of D1 receptors in DA-stimulated GH release. In studies using static incubation of pituitary cells, somatostatin, a known physiological GH-release inhibitor in the goldfish, abolished the GH response to DA. Intraperitoneal injection of apomorphine, a non-selective DA agonist, also increased the plasma GH levels and enhanced the linear body growth of goldfish. These results strongly suggest that DA, by acting through DA D1 receptors, functions as a GH-releasing factor in the goldfish.     

The vascular responses of the isolated perfused bovine external ear to exogenous histamine and 5-HT (serotonin)

The responses of the vasculature of isolated, non-sensitized, bovine external ears to histamine and serotonin (5-HT) were evaluated while they were being perfused with Krebs-Henseleit solution, Histamine (10^–5 mol/L to 5×10^–3 mol/L) and 5-hydroxytryptamine (5-HT) (10^–9 mol/L to 10^–2 mol/L) caused increased vascular resistance. Mepyramine (10^–7 mol/L), cimetidine (10^–5 mol/L) and atropine (10^–6 mol/L) inhibited the responses to histamine. The responses to 5-HT were inhibited by methysergide (10^–9 mol/L) and potentiated by morphine (10^–5 mol/L). These results suggest the presence of H₁ and H₂ histamine, and 5-HT receptors in bovine auricular vessels, all of which cause net vasoconstriction.     

伊氏锥虫与小鼠细胞的粘附反应研究

本文探讨了伊氏锥虫在体外与小鼠淋巴细胞、巨噬细胞和上皮细胞间的粘附反应。结果表明，三种健康细胞与锥虫有不同程度的粘附性，不同个体来源的细胞的粘附反应存在差异，但是，各类细胞的粘附率之比基本稳定。动物受到感染后，粘附细胞数大幅度减少。人α－干扰素可以促进健康细胞以及受感染动物细胞与锥虫的粘附性。细胞粘附水平高的个体在疾病的后期表现有较强的耐受力。作者认为，小鼠多种细胞表面存在着伊氏锥虫的病原性受体，后者与动物的抗锥虫感染能力以及疾病发生都有明显相关性。     

Endotoxaemia in dairy cattle:Mechanism of reticulorumen stasis

The objective of this study was to determine whether blockade of α₋₂ adrenergic receptors would restorereticulorumen motility during toxaemia in cows. Reticulorumen contractions were measured via a water-filled balloon connected to a pressure transducer. Intravenous infusion of endotoxin (100 ng kg⁻¹ over 30 min) significantly decreased the number of reticulorumen contractions. Intravenous infusion of yohimbine (125 μg kg⁻¹ over 30 min) alone did not affect reticulorumen contractions. However, when yohimbine (125 μg kg⁻¹ over 30 min) was infused concurrently with endotoxin (100 ng kg⁻¹ over 30 min), the effects of endotoxin on reticulorumen contraction frequency decreased, suggesting that endotoxaemia causes reticulorumen stasis via a mechanism that involves α₋₂ adrenergic receptors.