Lyophilized Powder This product is freeze dried. All water molecules have been removed.
Bioassay Tested Every lot is tried & tested in a relevant biological assay.
Our Bioassay
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- Albuquerque, E.X. et al. (2009) Physiol. Rev. 89, 73.
- Luetje, C.W. and Patrick, J. (1991) J. Neurosci. 11, 837.
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Alomone Labs (-)-Cytisine activates α2/β4 nicotinic acetylcholine receptor channels heterologously expressed in Xenopus oocytes.Current traces of α2/β4 nicotinic acetylcholine receptor channels activity at -60 mV holding potential. The bars above the trace represent periods where (-)-Cytisine (#C-130) or acetylcholine were applied at the indicated concentration.
- 1. Banko, P.C. et al. (2002) J. Chem. Ecol. 28, 1393.
- 2. Albuquerque, E.X. et al. (2009) Physiol. Rev. 89, 73.
- 3. Luetje, C.W. and Patrick, J. (1991) J. Neurosci. 11, 837.
- 4. Chavez-Noriega, L.E. et al. (1997) J. Pharmacol. Exp. Ther. 280, 346.
- 5. Papke, R.L. and Heinemann, S.F. (1994) Mol. Pharmacol. 45, 142.
- 6. Mineur, Y.S. et al. (2007) Neuropharmacology 52, 1256.
- 7. Reavill, C. et al. (1990) Neuropharmacology 29, 619.
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(-)-Cytisine is an alkaloid, which occurs naturally in several types of plants as well as in animals feeding on them (see example in reference 1). (-)-Cytisine is a potent and selective agonist of neuronal nAChR2. It acts as a partial agonist of β2-containing nAChR3.
EC50s differ for different subunit-composed channels; for recombinant human channels expressed in Xenopus oocytes the following EC50 values were reported: 25 µM, 39 µM, 67 µM, 72 µM, 2.6 µM 0.9 µM and 71 µM for α2/β2, α2/β4, α3/β2, α3/β4, α4/β2, α4/β4 and α7 respectively4.
However, in β2-containing channels, the response to acetylcholine (ACh) is largely reduced when applied in combination with (-)-Cytisine5. Therefore, when applied in vivo it exerts a compound effect of both activating certain nAchRs and inhibiting the effect of ACh on others. For example, (-)-Cytisine was found to have antidepressant-like effects in several animal models of antidepressant efficacy. This was probably achieved by inhibiting the effect of ACh on α2/β4 channel in the basolateral amygdala6.
In another study, the effects of (-)-Cytisine were compared to nicotine. Rats were trained to discriminate nicotine from saline and it was confirmed that (-)-Cytisine had a nicotine-like discriminative effect, but it was much less potent than nicotine itself7.
(-)-Cytisine (#C-130) is a highly pure, synthetic, and biologically active compound.
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目前大量制备单抗的方法主要有两大系统,一是动物体内生产法,这是国内外实验室所广泛采用;另一是体外培养法。
(1)动物体内生产单抗的方法
迄今为止,通常情况下均采用动物体内生产单抗的方法,鉴于绝大多数动物用杂交瘤均由BALB/c小鼠的骨髓瘤细胞与同品系的脾细胞融合而得,因此使用的动物当然首选BALB/c小鼠。本方法即将杂交瘤细胞接种于小鼠腹腔内,在小鼠腹腔内生长杂交瘤,并产生腹水,因而可得到大量的腹水单抗且抗体浓度很高。可见该法操作简便、经济,不过,腹水中常混有小鼠的各种杂蛋白(包括Ig),因此在很多情况下要提纯后才能使用,而且还有污染动物病毒的危险,故而最好用SPF级小鼠。
(2)体外培养生产单抗的方法
总体上讲,杂交瘤细胞系并不是严格的贴壁依赖细胞(anchoragedependentcell,ADC),因此既可以进行单层细胞培养,又可以进行悬浮培养。杂交瘤细胞的单层细胞培养法是各个实验室最常用的手段,即将杂交瘤细胞加入培养瓶中,以含10-15%小牛血清的培养基培养,细胞浓度以1×106-2×106/ml为佳,然后收集培养上清,其中单抗含量约10-50ug/ml。显然,这种方法制备的单抗量极为有限,无疑是不适用于单抗的大规模生产。要想在体外大量制备单抗,就必须进行杂交瘤细胞的大量(高密度)培养。单位体积内细胞数量越多,细胞存活时间越长,单抗的浓度就越高,产量就越大。
二、补体(complement,C)是存在于正常人和动物血清与组织液中的一组经活化后具有酶活性的蛋白质。早在19世纪末Bordet即证实,新鲜血液中含有一种不耐热的成分,可辅助和补充特异性抗体,介导免疫溶菌、溶血作用,故称为补体。补体是由30余种可溶性蛋白、膜结合性蛋白和补体受体组成的多分子系统,故称为补体系统(complementsystem)。根据补体系统各成分的生物学功能,可将其分为补体固有成分、补体调控成分和补体受体(CR)。


