高效液相色谱荧光检测法检测鸡蛋中氨苄西林残留

鸡蛋经乙腈提取,饱和二氯甲烷萃取,水杨醛酸性条件下沸水浴衍生后,以0.01mol.L-1的磷酸二氢钾溶液（A）和乙腈溶液（B）为流动相,流速为1.0mL.min-1,荧光检测激发波长为354nm,发射波长为445nm,建立了用高效液相色谱荧光法检测鸡蛋中氨苄西林残留的方法。氨苄西林在5.0～800.0μg.L-1,本方法线性关系良好,相关系数为0.999 4。当氨苄西林添加水平为5～125ng.g-1时,该方法平均回收率为78.30%～85.11%,相对标准偏差为4.99%～7.25%;日内相对标准偏差为7.99%～9.64%;日间相对标准偏差为8.69%～12.48%。氨苄西林检测限为0.4ng.g-1（S/N=3）,定量限1.5ng.g-1（S/N=10）。所建立的方法简便、快速、灵敏度高,适用于鸡蛋中氨苄西林残留的高灵敏度检测。     

猪脂肪沉积的品系差异及其cAMP的调控作用

体重、健康状况相近的８月龄混系和丹系长白肥育猪１６头，空腹采血测定ｃＡＭＰ、胰岛素、激素敏感脂酶（ＨＳＬ）、游离脂肪酸（ＦＦＡ）和甘油三酯；屠宰后测定胴体指标，并采背部脂肪和肝脏组织，分析了ｃＡＭＰ和腺苷酸环化酶（ＡＣ）活性以及脂肪组织中脂肪酸组成．结果表明，与混系相比，丹系瘦肉率、眼肌面积和后腿比分别高９．４４％（Ｐ＜０．０１）、９．６７％和４．００％，背膘厚、脂肪率和板油比分别低７．９７％、１８．１０％（Ｐ＜０．０５）和１４．２５％。血浆ｃＡＭＰ、ＨＳＬ和ＦＦＡ分别比混系高３２．８５％（Ｐ＜０．０５）、７．４１％和１２３．４１％；甘油三酯和胰岛素则分别低１２．２３％和１８．０６％．丹系脂肪组织中总脂，１４碳和１６碳脂肪酸分别高１０．８５％、３９．６６％（Ｐ＜０．０１）和７．３１％，而１８碳脂肪酸则低４．３１％；丹系肝和脂肪组织中ｃＡＭＰ和ＡＣ显著高于混系。结果证明，猪脂肪沉积的品系差异与肝、脂肪组织及血中ｃＡＭＰ的水平有关，脂肪沉积的ｃＡＭＰ调控具有明显的品系差异。     

Biochemical and functional characterization of lymphocytes from a horse with lymphosarcoma and IgM deficiency

Neoplastic lymphocytes from a horse with lymphosarcoma and IgM deficiency were analyzed for ability to grow in culture; surface and cytoplasmic IgM; functional activity in blastogenesis, cytoxicity, and suppressor assays; and activities of six enzymes involved in purine and pyrimidine metabolism. The cells lacked surface and cytoplasmic IgM. They had elevated activity of adenosine deaminase and reduced activity of purine nucleoside phosphorylase. Neoplastic cells were nonresponsive in blastogenesis assay and did not kill allogeneic lymphocyte target cells or YAC-1 targets in a lectin-dependent cytotoxicity assay, however, the cells were active in a suppressor assay. They were grown for 16 weeks in cultures supplemented with interleukin 2, during which time the cells retained suppressive activity. These results are consistent with a T cell lymphoma of suppressor cell origin, and may explain the deficiency of IgM observed in some horses with lymphoreticular neoplasms.     

Effect of Nao-re-qing oral liquid on cAMP content in hypothalamus and CSF,and AVP content in ventral septal area of endotoxin-induced febrile rabbits

AIM: To explore the mechanism of Nao-re-qing oral liquid (NRQ) decreasing endotoxin (ET)-induced fever in rabbits. METHODS: (1) The ET-induced fever model was established in rabbits. Febrile response of rabbits was observed. (2) The arginine vasopressin (AVP) content in the ventral septal area (VSA), and cAMP content in hypothalarmus (HP) and CSF were determined by radioimmunoassay.RESULTS: (1) In ET group, the maximal increment in body temperature (ΔT) [(1.80±0.16) ℃], 6 h thermal respone index (TRI₆)(11.31±0.20), the cAMP content in the HP [(1.35±0.21)nmol/g], the cAMP content in CSF [(66.69±1.82) nmol/L] and AVP content in the VSA [(30.80±9.59)ng/g ] were significantly higher than those in NRQ+ET group[ΔT(0.82±0.08) ℃, TRI₆(5.73±0.09), HP: cAMP(0.70±0.50)nmol/g, CSF: cAMP(56.86±1.34), AVP:(11.91±3.47)ng/g]( P<0.01). (2) The AVP content in VSA, and cAMP content in HP and CSF were separately paralleled with the fluctuation of body temperature (AVP: r=0.972, P<0.01; HP: cAMP r=0.899, P<0.05; CSF: cAMP r=0.991, P<0.01). CONCLUSION: The antipyretic action of NRQ may be due to inhibiting the increase in cAMP in HP and meanwhile promoting the release of AVP in VSA.     

三角帆蚌AMP基因cDNA全序列的克隆及分子特征研究

以三角帆蚌(Hyriopsis cumingii)为研究材料,根据实验室构建的三角帆蚌cDNA文库中已标注的EST序列,利用RACE克隆了三角帆蚌AMP基因的cDNA全序列。该cDNA序列全长为970 bp,5′端非翻译区123 bp,3′端非翻译区526 bp,开放阅读框(ORF)长为300 bp,共编码99个氨基酸,包含一段由27个氨基酸组成的信号肽和72个氨基酸的成熟肽,分子量为10 924.7 u。氨基酸序列分析表明,该序列存在明显的跨膜结构和疏水区。同源性分析表明,该基因编码的蛋白与海兔(Aplysia californica)theromacin氨基酸序列的相似度最高为56%,而与贻贝等中发现的抗菌肽defensins、mytilins、myticins和mytimycins相似度较低,推测属于抗菌肽theromacin基因家族。Jpred3软件对三角帆蚌AMP蛋白的二级结构预测结果表明,在第2~22、57~62氨基酸残基处存在α螺旋,因此,三角帆蚌的AMP蛋白是包含跨膜螺旋的膜蛋白。为进一步研究该基因的表达、功能及三角帆蚌病害防御奠定了分子基础。研究亮点:theromacin不属于常见的抗菌肽基...     

高效液相色谱法测定大鼠比目鱼肌和内侧腓肠肌内ATP·ADP及AMP含量的研究

[目的]比较成年大鼠比目鱼肌和内侧腓肠肌内ATP、ADP及AMP的含量。[方法]采用大体解剖法取出大鼠的比目鱼肌和内侧腓肠肌,置于液氮内研磨成粉末,再分别加入EDTA和HClO4、NaHCO3,经高速冷冻离心取出上清液,用高效液相色谱仪测定。[结果]慢肌(比目鱼肌)ADP的含量多于快肌(内侧腓肠肌),慢肌(比目鱼肌)ATP、AMP的含量少于快肌(内侧腓肠肌)。[结论]使用高效液相色谱仪可以检测出快慢肌的差异。     

AMP与ASA对菊花花瓣生理和花期调控的影响

以不同浓度的氨苄西林(AMP)+抗坏血酸(ASA)水溶液对菊花"唐宇金秋"品种在营养生长期和绿蕾期进行全株喷雾处理,测定整个花期花瓣可溶性蛋白、可溶性精含量、超氧化物歧化酶(SOD)活力、超氧阴离子(O2-)产生速率、丙二醛(MDA)含量、相对电导率及干鲜比的变化.结果表明,不同浓度AMP+ASA组合均能提高花瓣中SOD活力、可溶性蛋白和可溶性糖含量,降低花瓣中O2-产生速率、MDA含量和相对电导率,花期均有不同程度的延长,其中以AMP500 mg/L+ASA200 mg/L处理效果最佳.     

Biochemical and pharmacological characterization of adenosine A1 receptors in eel (Anguilla anguilla) brain

N⁶-cyclohexyl[³H]adenosine ([³H]CHA) was used to label adenosine A1 receptors in membranes prepared from male and female eel whole brain. The A1 receptor agonist [³H]CHA bound saturably, reversibly and with high affinity (K_d = 0.91 ± 0.12 nM; B_max = 120.36 ± 5.2 fmol mg⁻¹ protein). In equilibrium competition experiments, the adenosine agonists and antagonists all displaced [³H]CHA from high-affinity binding sites with the rank order of potency in displacing, characteristics of an A1 adenosine receptor. Mg²⁺ dramatically increased the affinity of [³H]CHA without modifying the maximal binding capacity. The specific binding was inhibited by guanosine 5′-triphosphate (K_i = 2.54 ± 0.98 μM). The [³H]CHA binding sites are ubiquitously distributed with a maximum in cerebellum and a minimum in olfactory bulb. No difference was observed between male and female brain. In eel brain, synaptosomes (P2), stimulation of adenosine 3′,5′-monophosphate (cyclic AMP) accumulation with 10⁻⁵ M forskolin was markedly reduced (45.5%) by treatment with the adenosine A1 receptor agonist CHA (10⁻⁴ M), and the reduction was reversed in presence of the selective A1 receptor antagonist 8-cyclopentyltheophylline (10⁻⁵ M). In superfused eel cerebellar synaptosomes, K⁺ stimulated the release of adenosine in a partially Ca²⁺-dependent manner. The findings, taken together, suggest the hypothesis that adenosine A1 receptors present in eel brain could modulate synaptic transmission, as A1 receptors do in other vertebrates.     

高效液相色谱荧光检测法检测鸡组织中氨苄西林残留量

[目的]为氨苄西林在鸡组织中的残留检测标准的制定提供科学依据。[方法]建立检测鸡组织中氨苄西林残留量的高效液相色谱荧光法。[结果]氨苄西林在25~1 000μg/kg浓度范围内,色谱峰面积与浓度呈线性关系,且线性关系良好。当氨苄西林添加量为10.0~125.0μg/ml时,鸡组织中AMP的平均回收率为71.23%~88.86%,相对标准偏差均低于10.74%;检测限和定量限分别为3.5(S/N=3)和10.0μg/kg(S/N=10)。[结论]该方法操作简便快速,可适用于鸡组织中氨苄西林的提取和检测,且准确度和精密度均符合残留分析的要求。     

Mechanisms of action of pituitary adenylate cyclase-activating polypeptide (PACAP) on growth hormone release from dispersed goldfish pituitary cells

The mechanisms of pituitary adenylate cyclase activating polypeptide (PACAP) action on goldfish growth hormone (GH) release were investigated by examining GH release responses from dispersed goldfish pituitary cells to a synthetic mammalian (m)PACAP₃₈ peptide. It was established that GH release stimulated by 2-h exposure to mPACAP₃₈ was concentration-dependent, attenuated by the PACAP receptor antagonist mPACAP_6–38, and subject to neuroendocrine modulation by somatostatin. Maximal mPACAP₃₈-stimulated GH release was not additive to the responses elicited by either the adenylate cyclase activator forskolin or the cyclic (c)AMP analog 8-bromo-cAMP. The GH responses to mPACAP₃₈, forskolin and 8-bromo-cAMP, either alone or in combination, were abolished by H89, a protein kinase A (PKA) inhibitor. SQ22536, an adenylate cyclase inhibitor, attenuated forskolin- and mPACAP₃₈-stimulated GH release. In contrast, mPACAP₃₈-stimulated GH release were additive to the responses to two protein kinase C (PKC) activators and unaffected by two PKC inhibitors. These results suggest that the stimulatory action of PACAP on GH secretion is mediated through a cAMP- / PKA-dependent mechanism, whereas the involvement of PKC appears unlikely. The ability of mPACAP₃₈ to further enhance maximal GnRH (PKC)-dependent GH release, but not dopamine D1 agonist (PKA)-dependent GH secretion, is consistent with this hypothesis. A possible involvement of Ca²⁺ in PACAP action is also suggested. Two inhibitors of voltage-sensitive Ca²⁺ channel reduced the GH responses to mPACAP₃₈ in static incubation; conversely, mPACAP₃₈ increased intracellular [Ca²⁺] in identified, single goldfish somatotropes.