Action of deltamethrin on N-type (Ca_v2.2) voltage-sensitive calcium channels in rat brain     

Steven B. Symington 《Pesticide biochemistry and physiology》2005,82(1):1-15

Isolated presynaptic nerve terminals prepared from whole rat brain were used to evaluate the action of deltamethrin on voltage-sensitive calcium channels by measuring calcium influx and endogenous glutamate release. Deltamethrin-enhanced K⁺-stimulated calcium influx and subsequent Ca²⁺-dependent glutamate release. The effect of deltamethrin was concentration-dependent, stereospecific, blocked by ω-conotoxin MVIIC but unaltered in the presence of tetrodotoxin. These results suggest that N-type voltage-sensitive calcium channels are a site of action at the presynaptic nerve terminal. Electrophysiological studies were carried out using rat brain Ca_v2.2 and β₃ subunits coexpressed in Xenopus oocytes to validate such action. Deltamethrin reduced barium peak current in a concentraion-dependent and stereospecific manner, increased the rate of activation, and prolonged the inactivation rate of this channel. These experiments support the conclusion that N-type voltage-sensitive calcium channel operation is altered by deltamethrin.  相似文献   

利用甜高粱秸秆汁产单细胞蛋白的分批补料发酵研究     

庞会忠  叶亚健  王飞  程新  吴晓玉  李昆太 《中国饲料》2012,(3):19-21

本文以甜高粱秸秆汁为主要的发酵原料,对热带假丝酵母SG-1在15-L罐上产单细胞蛋白(SCP)的分批补料发酵过程进行研究。首先对分批发酵模式下的菌体代谢过程变化进行研究。研究发现,接种后菌体快速进入繁殖阶段,但是总糖在12 h处于耗竭状态,使得菌体量和SCP产量过早的在18 h就达到峰值。基于此,在15-L罐上建立了热带假丝酵母SG-1产SCP的分批补料发酵模式。结果表明:菌体代谢因基质的补加而得到进一步的延续,放罐时(42 h)其菌体干重和SCP产量分别达19.86 g/L和9.93 g/L,显著高于分批发酵模式的10.45 g/L和4.70 g/L。  相似文献   

Effects of Donor Cells Treated with Egg Extracts on the Development Competence of Cloned Embryos     

GUO Qin-qin  FAN Zong-xing  Hao Hai-sheng  LIU Yan  ZHAO Xue-ming  ZHU Hua-bin  DU Wei-hua 《中国畜牧兽医》2016,43(2):477-486

Japanese Balck cattle fetal fibroblasts (JBCFF) were induced with Xenopus leavis egg extracts and somatic cell nuclear transfer (SCNT) was carried out with the reprogrammed JBCFF as donor cells in order to investigate their effects on SCNT efficiency.Three samples of egg extracts were acquired from different Xenopus laevis.The protein contents and kinds in extracts were evaluated with BCA Protein Quantification Kit and SDS-PAGE.Concentration of Digitonin to permeabilize JBCFF was optimized and assessed with PI staining.Reprogrammed cells treated with egg extract were used as donor in SCNT.Additionally the reconstructed embryos were activated with ionomycin+6-DMAP and A23187+6-DMAP to compare their effects on the development competence.The protein contents of extracts samples were 56.2255,64.6570 and 71.2158 μg/mL,respectively,the each extract had the same composition about 40-55 and 70-100 ku.The optimal concentration of Digitonin was 7 μg/mL and the permeabilization rate was 55.44%.After extracts treatment and continuous culture for 6-7 d,JBCFF formed well-defined colony structures.No significant composition difference was found in rates of fusion (92.83% vs 96.04%),cleavage (89.64% vs 89.78%) and blastocyst formation (24.06% vs 23.12%) of cloned embryos when the colony cells and JBCFF without extracts treatment were used as donor cells (P>0.05).Similarly,the two activation methods had no significant effect on the developmental competence of cloned embryos (cleavage rate 92.16% vs 92.28%,blastocyst rate 23.21% vs 24.18%).Conclusively,Xenopus leavis,egg extracts could induce JBCFF reprogramming to a low differentiated state.However donor cells with reprogramming partially could not improve the development of cloned embryos and its mechanism requires further research.  相似文献   

利用假丝酵母进行棉仁饼固体发酵的培养基筛选   总被引：4，自引：0，他引：4  

孙建义  许梓荣 《浙江大学学报(农业与生命科学版)》1998,(6)

以棉仁饼为原料,热带假丝酵母ＺＡＵ－１为菌种,采用固体发酵技术,对无游离棉酚的酵母饲料进行了研究,探讨了不同原料对酵母饲料发酵的影响,筛选出较合理的固体发酵培养基：棉仁饼６０％,大米蛋白粉２５％,麸皮１０％,饴糖２％,酒糟１％,ＭｇＳＯ４５Ｈ２Ｏ０．２５％,ＫＨ２ＰＯ４０．７５％,ＦｅＳＯ４７Ｈ２Ｏ０．８０％,ＺｎＳＯ４７Ｈ２Ｏ０．２０％,ＭｎＳＯ４Ｈ２Ｏ０．０６％,ＣｕＳＯ４５Ｈ２Ｏ０．０４％和ＣｏＣｌ２６Ｈ２Ｏ０．０２％．  相似文献   

Vagrant Subantarctic fur seal on the coast of Tanzania     

《African Zoology》2013,48(1):144-146

An immature Subantarctic fur seal was sighted on Unguja Island, Zanzibar, Tanzania, in 2008. This is the most northerly record of a vagrant of this species. The nearest breeding colony is on the Prince Edward Islands, 4500 km distant. While it is likely that this is the natal site of the vagrant due to its proximity and population size, the actual location of origin is unknown. This is the second fur seal sighted in this area. A fur seal of unknown species was sighted on Pemba Island, 30 km north of the Unguja Island, in 2002. While the species of the latter animal could not be determined, it is likely also a Subantarctic fur seal.  相似文献   

异色瓢虫对松大蚜和板栗大蚜选择效应研究     

朱强 《现代农业科技》2014,(11):123+128

异色瓢虫是徂徕山林场常见天敌之一,在实验室条件下,测定了异色瓢虫对徂徕山林场2种重要蚜虫板栗大蚜和松蚜的选择效应。结果表明,当2种蚜虫种群数量同步增加,则取决于瓢虫原来的生境和饲喂条件,当板栗大蚜或松蚜种群上升时,则喜好取食种群数量大的蚜虫。  相似文献   

Effect of nutrient compositions in peat hydrolysate on protein and biomass yields of Candida tropicalis     

F. -H. Chang 《Biology and Fertility of Soils》1986,2(4):187-194

Summary Research was conducted to study the effect of nutrient compositions, at different levels, added in peat hydrolysates on biomass yields and protein of Candida tropicalis. Samples of Minnesota sphagnum peat were hydrolyzed by boiling at 100°C with 1-1 H₂SO₄ solutions to produce peat hydrolysates which can support the growth of yeast. Peat hydrolysates were adjusted to pH 5.5 and mixed with mineral nutrients (NH₄NO₃, NaH₂PO₄ + Na₂HPO₄, KCl, and MgSO₄) and glucose. Among the single nutrients tested, glucose produced the most significant enhancement of biomass yields, followed by NH₄NO₃, NaH₂PO₄ + Na₂HPO₄, KCl, and MgSO₄. NH₄NO₃ was found to be the most important single nutrient affecting protein accumulation in yeast cells, followed by glucose > NaH₂PO₄ + Na₂HPO₄ > KCl > MgSO₄. However, protein and biomass production was significantly (P 0.05) greater for combined nutrients than for any single-nutrient enrichment. The level of residual reducing sugars in peat hydrolysate was inversely proportional to cell counts and optical densities. Addition of high concentrations of nutrients delayed the time of reaching to stationary phase in optical density, cell counts, and pH of yeast cultures. In general, as nutrients were increased, significant (P 0.05) increases in productivity and cell density were observed. However, specific growth rate decreased with increasing nutrient concentrations. It was concluded that nutrient amendments containing supplementary sources of C/N/P/K/S = 400:36:3.3:3.8:1 are most suitable for biomass production and the biosynthesis of protein by C. tropicalis.  相似文献   

非洲爪蟾卵子发生过程中凝集素(Lectin)分布的免疫组化研究   总被引：1，自引：0，他引：1  

谭景和  S.E.Zalik 《东北农业大学学报》1988,(2)

本文简述了动物内源性凝集素的研究概况和进行凝集素免疫组化研究的基本方法,并报道了对非洲爪蟾卵子发生过程中凝集素分布情况的下列初步研究结果:各发育阶段爪蟾卵母细胞膜都含有凝集素;皮质颗粒是爪蟾卵母细胞质内唯一含有凝集素的结构;皮质颗粒虽然于卵母细胞发育第Ⅱ阶段开始产生,但只是到笫Ⅲ阶段时才含有大量的凝集素——进行免疫荧光染色时,发亮绿色荧光。  相似文献   

植物雌激素槲皮素对非洲爪蟾生长和骨骼发育的影响     

丛琳  秦占芬  蒋湘宁  周景明  杨蕾  徐晓白 《勤云标准版测试》2005,(6)

用两栖动物非洲爪蟾作模型动物,来揭示植物雌激素槲皮素对非洲爪蟾生长和骨骼发育的影响。非洲爪蟾从46/47期开始,分别暴露50μg/L,100μg/L,200μg/L槲皮素,直至变态后1个月。结果表明槲皮素处理一方面促进蝌蚪体重的增加,另一方面导致尾的畸形。200μg/L槲皮素还导致脊柱的畸形,表现为少一块脊椎骨。  相似文献   

固态热带假丝酵母菌菌剂的发酵工艺研究     

刘政  李笑宇 《饲料研究》2021,(3):59-64

试验在单因素优化试验的基础上,采用正交试验进一步对热带假丝酵母菌固态发酵工艺进行研究,包括发酵时间、接种量、料水比、碳源、氮源、无机盐等因素,最终确定热带假丝酵母菌的固态发酵工艺。发酵条件:在自然pH值条件下,发酵温度30℃、发酵时间48 h、接种量11%、料水比1∶0.75。培养基成分:麸皮与甘油8.5∶1.5 (g/g)、尿素0.5%、磷酸二氢钾0。依照此工艺进行发酵,热带假丝酵母菌活菌数最高可达32.94×10⁸个/g。  相似文献