Effects of 5-Hydroxytraptamine on Aggregation,Release Reaction and Mobilization of Cytosolic Free Calcium Concentration in Rabbit Normal and Washed Single Platelets

In rabbit platelet rich plasma (PRP), 5-hydroxytraptamine (5-HT,0.03～3μmol/L) induced decrease in light transmission (DLT) dose-de pendently with centralization, as revealed by electron microscopy. However, 5-HT did not induced platelet aggregation and release reaction. 5-HT-induced DLT was inhibited by methysergide (0.3～30μmol/L), indomethacin (0.3～10μmol/L) and PGE_1 (0.01～0.3μmol/L) in a dose-dependent manner, but not EGTA(0.3～3mmol/L). Collagen(Coll), arachidonic acid (AA), adenosine diphosphate (ADP) and a stable thromboxane A2 analoge(STA_2) also induced DLT before aggregation by themselves, which was also inhibited by PGE_1, but not inhibited by EGTA except for Coll However,Coll-, AA-, STA_2-and ADP-induced DLT were reduced by pretreatment of PRP with 5-HT dose-depen-dently. The duration of DLT by Coll and AA were decreased from 151.4±5.93 sec and 15(?)38±0.60sec to 45.44±4.04 sec and 9.00±1.25 sec respectively ((?)±s(?) P<0.01), but not by ADP and STA_2, 3μmol/L of ADP-and 0.3μmol/L of STA_2-induced aggregation which was not accompanied with release reaction were enhanced by 5-HT pretreatment, but in those (Coil 5μg/ml, AA 100～200μmol/L and STA_2 1～3 μmol/L) with release reaction, the amount of adenosine triphosphate(ATP)were suppressed significantly (P<0.001) by 5-HT pretreatment without the effect on the magnitude of aggregation, The mobilization of cytosolic free calcium concentration ([Ca~(2+)]i) was observed after 5-HT treatment in single washed platelet, the results indicated that the basic level of [Ca~(2+)] i was 64.78±3.24nmol/L and this level was increased dose-dependently and significantly at 30 sec after administration of 5-HT and the time of peak value of [Ca~(2+)] i was at 90～100 sec.The similar time courses of suppression of ATP released during aggregation, in cases of Coll(5μg/ml), AA (200μmol/L) and STA_2(3μmol/L), by 5-HT were also found in the present experiment.     

外周伤害性刺激及吗啡对大鼠丘脑束旁核痛抑制-兴奋神经元电活动的影响

应用细胞外微电极技术,观察和记录了Pf痛反应神经元对伤害性夹尾、伤害性电刺激坐骨神经和检验性刺激及脑内微量注射吗啡前后电活动变化的情况。在67只Wistar大鼠右侧Pf内记录了309个痛反应神经元,其中PI-EN64个,占神经元总数的20.71%。PI-EN对伤害性夹尾和电刺激坐骨神经均发生特异性的抑制-兴奋反应,对非伤害性刺激则不发生反应。伤害性刺激诱发放电之前有     

盐酸小檗胺对豚鼠离体工作心脏的作用

用Tyrode液灌流豚鼠工作心脏,可使工作心脏的有效工作时间达60min。盐酸小檗胺(Berbamine,BA)能依剂量性地抑制豚鼠工作心脏,3μmol/L BA分别使左室收缩压(LVP)、主动脉压(AP)、主动脉流量(ABF)、冠脉流量(CBF)和总输出量(T-CO)等指标降低,使左室舒张末期压(LVEDP)升高;100μmol/L BA可使心室停搏,各项心功能指标趋近于零。1μmol/L BA能明显地对抗1μmol/L肾上腺素诱发工作心脏产生的心律失常。     

小檗胺对ATP诱导的培养平滑肌及心肌细胞内游离钙动员的影响

目的:研究小檗胺(Ber)对ATP诱导的细胞内钙动员的作用。方法:以Fura 3-AM负载培养的VSMC和心肌细胞,共聚焦技术检测细胞内钙荧光强度的变化。结果:(1)ATP使VSMC和心肌细胞内钙升高,但VSMC核区不明显。(2)Ber对静息荧光强度无影响,但降低ATP升高的胞内钙(P<0.01),Ber 100μmol·L~(-1)延长达峰值的时间(P<0.01),并不能完全抑制ATP升高的胞内钙。(3)在无外钙时,Ber对ATP诱导的胞内钙升高无抑制作用(P>0.05)。(4)Ber的作用与维拉帕米(Ver)相似。结论:ATP引起细胞外钙内流和内钙释放,Ber可阻断ATP引起的外钙内流,对其内钙释放无影响。     

大鼠尾-壳核内一种特殊类型的痛反应神经元

采用常规的鉴定方法，在43儿雄性Wistar火鼠的尾-壳核内共筛选了80个痛反应神经元，其中痛兴奋神经元为58个，痛抑制冲经元为22个。实验发现，同是痛兴奋神经元其自发放电的频率差别较大，痛诱发放电的潜伏期相差也较为悬殊，最短的为100ms，最长的可达3200ms。     

家兔血小板密度与其功能间的关系

很多研究提出血小板在功能、大小、密度、寿命、超微结构、生化组成等方面存在着异质性,但对血小板密度的异质性尚有不同见解。某些研究表明血小板在生存期中密度减低,而某些研究表明随着血小板的衰老伴有轻度的密度增加,并且由于生物种类的不同及用于分离血小板密度亚群的方法不同而有差异。在血小板聚集过程中,微管和微丝的重排、血小板形态的改变、伪足的形成、纤维蛋白原与受体联接等过程中,Ca~(2 )均起着重要作用。本实验以Perco11间断梯度离心法探讨了家兔血小板密度、大小,用凝血酶诱导洗脱血小板聚集、释放以及与细胞内游离钙动员的关系。     

关于NO Synthase译文的问题

关于ＮＯ　Ｓｙｎｔｈａｓｅ译文的问题李柏岩，李文汉（哈尔滨医科大学药理教研室，哈尔滨１５００８６）中国图书分类号Ｒ９１４．３近年来ＮＯ的发现已引起学术界广泛关注。最近国内许多刊物关于ＮＯ问题的报道，几乎无一例外地把ＮＯＳｙｎｔｈａｓｅ译为ＮＯ合成酶。...     

伤害性刺激及吗啡对丘脑束旁核痛抑制-兴奋神经元痛诱发放电的影响

大量电生理研究证明丘脑束旁核(pf)内存在两种痛反应神经元,即痛兴奋神经元(PEN)和痛抑制神经元(PIN)。本研究表明在丘脑pf内还有另外一种痛抑制-兴奋神经元(PI-EN)存在。309个pf痛放电单位,PI-EN64个,占20.7%,PEN和PIN分别为145和100个。实验结果表明PI-EN对末梢伤害性剌激呈现先兴奋后抑制反应,并且PI-EN具有痛反应神经元的共同特征。尾核头部及腹腔内注射吗啡均可减少PI-EN对伤害性剌激的反应,这一结果与吗啡对PEN和PIN的影响相似,且吗啡的上述结果可被纳洛酮阻断。     

人血小板密度亚群在聚集反应,ATP释放及细胞内游离钙浓度的异质性(英文)

目的:研究人血小板密度亚群在聚集和释放反应及细胞内钙浓度的异质性。方法:Percoll间断梯度离心法。结果:正常人血小板分为高(HD),中(ID)和低(LD)密度三个亚群。血小板的大小随密度的降低而减小(r=0.978,P<0.01)。HD对凝血酶(Thr),ADP和血清素(5-HT)诱导的聚集反应明显强于LD(P<0.01),ATP释放反应,除5-HT无ATP释放外,与聚集反应的结果一致。尽管细胞内游离钙([Ca~(2 )]_i的静息水平各亚群相同,但Thr,ADP和5-HT的[Ca~(2 )]_i动员仍以HD最为明显。结论:人HD血小板的功能及活性均高于LD血小板。