Fazeli M S, Errington M L, Dolphin A C, Bliss T V
Department of Pharmacology and Clinical Pharmacology, St. George's Hospital Medical School, London, U.K.
Brain Res. 1990 Jun 25;521(1-2):247-53. doi: 10.1016/0006-8993(90)91549-v.
In a previous communication, we reported an increase in protein efflux into perfusates obtained from push-pull cannulation of the dentate gyrus, following induction of long-term potentiation (LTP) in the perforant path. LTP was accompanied by a delayed but general increase in protein efflux. Protein B5 (MW 14 kDa), because of its relatively high concentration in the perfusates and absence from serum, has been chosen for further characterization. Spectrophotometric analysis, in situ proteolysis, two-dimensional electrophoresis and immunoblotting, revealed that protein B5 is indistinguishable from haemoglobin. A persistent increase in an 80 kDa protease, detected by SDS-PAGE zymography, was also seen after the induction of LTP. We consider the possibility that the increased haemoglobin content of perfusates after the induction of LTP may reflect an LTP-associated increase in the release (or activation) of proteases into extracellular space, leading to proteolytic breakdown of blood clots in the vicinity of the cannula. Evidence in favour of this hypothesis is provided.
在之前的一篇通讯中，我们报道了在穿通通路诱导长时程增强（LTP）后，从齿状回推挽式插管获得的灌流液中蛋白质流出增加。LTP伴随着蛋白质流出的延迟但普遍增加。蛋白质B5（分子量14 kDa）由于其在灌流液中的相对高浓度以及血清中不存在，已被选择进行进一步表征。分光光度分析、原位蛋白水解、二维电泳和免疫印迹显示，蛋白质B5与血红蛋白无法区分。通过SDS-PAGE酶谱法检测到，LTP诱导后80 kDa蛋白酶也持续增加。我们认为，LTP诱导后灌流液中血红蛋白含量增加可能反映了与LTP相关的蛋白酶向细胞外空间释放（或激活）增加，导致插管附近血凝块的蛋白水解分解。本文提供了支持这一假设的证据。
