MS-302三道测量分析系统的应用及HI-6在离体膈神经-膈肌上抗梭曼的作用机制探讨

目的 探讨抗神经毒化合物HI-6在离体膈神经．膈肌上抗梭曼的作用机制。方法采用MS．302三道测量分析系统,观察大鼠离体膈神经．膈肌的收缩功能,同时,测定膈肌乙酰胆碱酯酶（AChE）活性,观察药物对膈肌AChE活性的直接影响。结果（I）采用MS．302三道测量分析系统对膈神经．膈肌标本强直收缩曲线下的面积进行测量．较为直接地反映了膈神经．膈肌标本的生理功能,结果精确。（2）HI-610和100μmol／L对正常膈神经．膈肌收缩功能影响不明显,1mmol／L对正常膈神经．膈肌收缩功能有抑制作用。HI-610μmol／L预防和治疗给药时．对梭曼抑制的标本收缩功能既没有保护作用也没有拮抗作用;100μmol／L给药有一定的保护和拮抗作用;剂量增加到1mmol／L时。保护作用和拮抗作用都明显增强,且保护作用在30min内最佳。（3）预先给予HI-6不能减弱梭曼对大鼠离体膈肌AChE的抑制．梭曼中毒后给予HI．6对梭曼抑制的膈肌AChE活性无显著影响。结论HI．6对梭曼抑制的离体膈神经．膈肌收缩功能的恢复可能是直接生理对抗作用,在本实验条件下未见膈肌酶活力有明显的恢复。     

HI-6对正常及梭曼抑制大鼠离体膈神经-膈肌标本收缩功能的影响

目的　探讨HI 6对抗梭曼中毒所致呼吸抑制重活化作用外的其他可能作用机制。方法　采用MS 30 2三道生理记录仪 ,建立大鼠离体膈神经 膈肌收缩标本 ,观察HI 6对梭曼中毒膈神经 膈肌标本收缩功能的影响。结果　①梭曼 (2mg·L- 1)中毒后 ,膈肌收缩功能明显下降 ,中毒 10min内强直收缩曲线下面积下降至最低点 ,且在 3h内无明显恢复。②梭曼中毒前给予不同浓度的HI 6 (0 .0 1,0 .1,1.0mmol·L- 1) ,发现HI 6 (0 .1,1.0mmol·L- 1)对梭曼中毒所致膈肌强直收缩具有明显保护作用 ,且保护作用随着浓度的增加逐渐增强。③梭曼中毒后再给予HI 6 (0 .0 1,0 .1,1.0mmol·L- 1) ,发现 0 .0 1mmol·L- 1HI 6对中毒大鼠离体膈肌收缩功能无任何拮抗作用 ;当浓度增至 0 .1mmol·L- 1时 ,对膈肌强直收缩有一定的拮抗作用 ,但无统计学意义 ;但 1.0mmol·L- 1HI 6可显著对抗梭曼中毒所致膈肌收缩功能下降。结论　HI 6对梭曼中毒所致大鼠离体膈神经 膈肌收缩功能抑制具有明显拮抗作用 ,提示HI 6对抗梭曼中毒所致呼吸抑制作用机制存在酶保护作用外的直接生理对抗作用     

MS-302三道测量分析系统的应用及HI-6在离体膈神经-膈肌上抗梭曼的作用机制

目的 呼吸肌麻痹是有机磷酸酯类化合物严重中毒致死的主要原因之一,由于膈肌是最主要的呼吸肌,因此,建立一种精确灵敏的实验方法评价药物对离体膈神经 膈肌的影响, 探讨相应的抗呼吸肌麻痹药物的实验显得尤为重要。本文在MS-302三道测量分析系统上探讨了抗神经毒有效化合物HI-6在离体膈神经-膈肌上抗梭曼的作用机制。方法 采用MS-302三道测量分析系统,观察大鼠离体膈神经-膈肌的收缩功能,此方法较既往测量方法实时、高效而灵敏。观察膈肌收缩功能的同时,待标本稳定30 min后取膈肌置-20℃冰箱,留待测定正常乙酰胆碱酯酶(AChE)活性,然后向麦氏槽中加入以台式液配置的药物,加入药液量一般不超过0.5 ml,使药物浓度为10 μmol·L^-1～1 mmol·L^-1, 对照组加入等量的生理盐水, 于加药后不同时间点留取膈肌样品测定AChE活性,观察药物对膈肌AChE活性的直接影响。结果 ① MS-302三道测量分析系统上,对膈神经-膈肌标本强直收缩曲线下的面积进行测量,能较为直接的反映膈神经-膈肌标本的生理功能,且结果精确。② HI-6 10和100 μmol·L^-1对正常膈神经-膈肌收缩功能影响不明显,当药物浓度为1 mmol·L^-1时, HI-6对正常膈神经-膈肌收缩功能有抑制作用;HI-6 10 μmol·L^-1对梭曼抑制的标本收缩功能既没有保护作用也没有拮抗作用; HI-6 100 μmol·L^-1有一定的保护和拮抗作用;当剂量增加到1 mmol·L^-1时,HI-6的保护作用和拮抗作用都明显增强,且保护作用在30 min内最佳。③ 预先给予HI-6不能减弱梭曼对大鼠离体膈肌AChE的抑制,提示HI-6对梭曼抑制的大鼠离体膈肌AChE无明显保护作用;梭曼中毒后给予HI-6对梭曼抑制的膈肌AChE活性无显著影响,提示HI-6对梭曼抑制的膈肌AchE无明显重活化作用。结论 HI-6对梭曼抑制的离体膈神经-膈肌收缩功能的恢复可能是直接生理对抗作用,在本实验条件下未见膈肌AChE活力有明显的恢复。     

敌敌畏对大鼠膈肌的直接毒性作用

目的　观察敌敌畏是否对膈肌具有直接抑制作用。方法　用自制双功能电极剌激膈神经或直接剌激离体大鼠膈肌 ,引起膈肌收缩 ,观察农药敌敌畏对膈肌的直接抑制作用。用箭毒阻断神经肌肉接头后 ,剌激膈神经不再引起膈肌收缩 ,直接刺激膈肌引起的收缩与神经肌肉接头无关 ,对这种收缩的影响为对膈肌的直接作用。结果　 10V直接刺激膈肌出现类似于强直收缩的波形。敌敌畏浓度大于1.4 5mmol·L- 1时可使该收缩显著抑制 ,4 .34mmol·L- 1时抑制 80 % ,5 .79mmol·L- 1完全抑制 ,氯磷定不能减轻之。浓度大于 3.62mmol·L- 1的敌敌畏对单收缩也有明显抑制。结论　敌敌畏对膈肌具有与神经肌肉接头阻断无关的直接抑制作用     

MS-302三道生理信号测量分析系统应用及神经刺激装置的改进

目的 呼吸肌麻痹是有机磷酸酯类化合物严重中毒致死的主要原因之一，由于膈肌是最主要的呼吸肌，因此，建立在离体或在体膈神经-膈肌标本上寻找相应的抗呼吸肌麻痹药物的实验显得尤为重要。以往观察离体膈神经-膈肌标本的实验，多是在记纹鼓或平衡记录仪上进行的。它们均有一定的缺点。为此，我们率先引进了MS-302三道生理信号测量分析系统，该系统具有精确性高、可控性强及灵敏度好等优点，很好的满足了实验的要求。此外，实验中我们发现MS-302三道记录仪系统中的神经刺激器存在一定的局限性。如该刺激器只存在刺激膈神经的电极，只能刺激膈神经而不能刺激膈肌；只能用于研究整个膈神经-膈肌肌肉系统的功能状态，不能对神经-肌肉接头及膈肌本身的功能状态进行分别观察。针对上述缺点，我们对原有的单功能刺激电极进行了改进，改进后的刺激电极，可对肌肉和神经同时，分别或交替进行连续或不连续的刺激，并能将两者明确分开，可广泛应用于医学和生物学领域的各种实验，检测、生产和临床医疗。上述技术革新成果已成功申请专利(专利号为02247761．6)。     

青藤碱对神经肌肉传递的作用

青藤碱对大鼠离体膈神经隔肌标本能可逆性阻滞神经肌肉的传递,呈浓度依赖性抑制作用;对神经干的兴奋性和传导性无明显影响。高Ca~(2+)溶液可拮抗青藤碱对神经肌肉传递的阻滞作用。在小鸡颈二腹肌实验,青藤碱可降低肌肉对ACh的敏感性。青藤碱与琥珀胆碱相似,均使蟾蜍腹直肌标本产生收缩反应。新斯的明不能桔抗青藤碱对神经肌肉传递的阻滞作用,且有加强作用。提示青藤碱具有去极化型肌松药的某些作用特点。     

家兔膈的形态和神经支配分布的研究

目的 对家兔膈的形态和肌内神经分支分布的研究,提供兔膈的形态学资料,为人膈的研究提供比较解剖学的资料.材料和方法 家兔15只,其中5只用大体解剖法观察膈的形态,另外10只用Sihler's肌内神经染色法研究膈的神经分支分布.结果 (1)家兔的膈为扁薄的阔肌,分为四部分:中心腱、胸骨部、肋部和膈脚.中心腱较大,居膈的中央,周边为短肌束排列构成的环状肌质带.胸骨部为短肌;肋部为带状肌,其肌束呈栅栏状并行排列;膈脚近似梭形肌.膈肌没有羽状角.(2)神经分布:膈的肋部、胸骨部和膈脚各有膈神经的1～2支一级神经分支支配.各级神经分支在各部肌束中部吻合形成一较为稀疏的神经网或神经带.下6对肋间神经分支非常靠近膈的肋部.结论 (1)家兔的膈分为四部分:中心腱,胸骨部,肋部和膈脚.膈肌均为横跨肌肉起止点的短纤维构成.(2)家兔膈主要由膈神经支配.     

HI-6 等对抗有机磷农药抑制离体大鼠膈肌的研究

ＨＩ┐６等对抗有机磷农药抑制离体大鼠膈肌的研究王汉斌赵德禄１黄韶清（军事医学科学院附属医院，北京１０００３９；１北京毒物药物研究所，北京１００８５０）本研究观察了ＨＩ－６及常用肟类重活化剂氯磷定，碘磷定及双复磷等对抗ＤＤＶＰ对离体大白鼠膈神经膈肌标本...     

吡喹酮对神经肌肉接头传递的作用

吡喹酮可使电刺激腓总神经所引起的胫前肌收缩反应明显加强。如给腓总神经施加超强刺激,静脉注射筒箭毒碱可减弱肌肉收缩反应,吡喹酮却能加强筒箭毒碱的抑制作用,使神经肌肉传递迅即完全阻断。采用微电极细胞内记录技术研究吡喹酮对离体大鼠膈神经隔肌的作用,发现吡喹酮不明显影响膈肌细胞的静息膜电位。低浓度吡喹酮(2×10~(-4)M)可使微终板电位(mepp)频率明显增加。高浓度吡喹酮8×10~(-4)M则使mepp振幅逐渐变小和消失。吡喹酮在使神经肌肉传递阻滞不断加深的同时,尚能使终板电位的振幅变小,终致完全消失。     

Gen,Amk及Tub的骨骼肌松弛作用的比较

为定量研究庆大霉素(Gen)和丁胺卡那霉素(Amk)的肌松作用,进行了小鼠攀网、小鸡垂头和大鼠膈神经-膈肌离体标本的研究.结果表明,Gen和Amk的肌松作用与筒箭毒碱(Tub)相似均呈非去极化型,Gen的肌松强度约为Amk的2倍.Gen的神经肌接头阻滞作用几呈全或无型反应,其S值明显大于Tub.模拟药物消除,Tub药效呈顺时钟袢而Gen呈逆时钟滞后.     

Inhibition of nicotinic responses at neuromuscular junctions by 3,3-dimethyl-1-butanol carbamate (DBC)

The action of 3,3-dimethyl-1-butanol carbamate (DBC), a synthetic carbachol analogue in which the quaternary nitrogen atom has been replaced by a carbon atom, has been studied in relation to its effects on nicotinic responses. In the thick biventer cervicis nerve-muscle preparation and frog rectus abdominis muscle preparation, DBC inhibited the responses elicited by nicotine and dimethylphenylpiperazinium at concentrations that did not affect responses induced by acetylcholine. DBC (^?4–10^?3M) depressed markedly the uptake of ³H-nicotine (2 × 10^?3M) into the frog rectus abdominis muscle preparation. In the innervated chick biventer cervicis nerve-muscle preparation, DBC (10^?3M) also decreased the uptake of ³H-nicotine (2 × 10^?3M), but in denervated preparations, DBC had no effect. It is concluded that the peripheral antinicotinic actions of DBC require an intact nerve-muscle junction and are due to a blockade in the uptake of nicotine into nerve fibers.     

Carbachol-methohexitone interactions at the chick neuromuscular junction: Experiments with the moving fluid electrode technique

The moving fluid electrode was used to record simultaneously the depolarization and contracture responses produced by drug action. Carbachol (CCh) (5.5 × 10^?6 ?5.5 × 10^?4M) and acetylcholine (ACh) (5.5 × 10^?6 ? 1.1 × 10^?2M) produced large depolarization and contracture responses in the isolated chick biventer cervicis (BVC) muscle. These responses were greatly reduced by methohexitone (8.8 × 10^?5 M). The concentration-response curves for ACh and carbachol in the control Krebs solution were shifted in the presence of methohexitone to the right in a non-competitive manner. The present results indicate that both ACh and carbachol act postjunctionally by depolarizing the membrane and producing contractures in the chick biventer cervicis muscle.     

金环蛇(Bungarus fasciatus)蛇毒的分离及其毒性组分的药理研究

金环蛇毒用羧甲基纤维素柱层析分离出17个蛋白组分,其中5个组分是毒性较大的致死成分。在这5个组分中,Ⅺ、Ⅻ、ⅩⅤ是心脏毒,ⅩⅢ、ⅩⅣ是神经毒。心脏毒组分Ⅺ、ⅫⅩⅤ使离体大鼠心脏挛缩,心跳停止于收缩期;使小鸡离体颈二腹肌挛缩,最后致痉挛性麻痹;对兔眼结合膜有局部刺激作用,使结合膜充血水肿。组分ⅩⅤ还具有直接溶血作用。神经毒组分ⅩⅢ阻断大鼠、小鸡、青蛙神经肌肉标本的突触传递,标本对乙酰胆碱的反应消失,对直接刺激以及对高浓度氯化钾的反应无减少,神经末梢乙酰胆碱的释放最无显著改变;使蛙腹直肌乙酰胆碱量效曲线平行右移,新斯的明可以对抗这个作用。组分ⅩⅣ的作用与组分ⅩⅢ相似。实验提示,组分ⅩⅢ、ⅩⅣ是作用于终板后膜的神经毒。     

Cholinergic receptor labelling specific irreversible binding of bromoacetylcholine to cholinergic receptors at neuromuscular junctions

This study shows that (a) the slopes of dose-response curves of bromoacetylcholine (BrACh) and acetylcoline (ACh) were the same; (b) the dose-response curves of BrACh to contract superfused chick biventer cervicis and frog rectus abdominis muscles were shifted to the right by d-tubocurarine in a parallel fashio; and (c) the responses of BrACh were not affected by triethylcholine, which paralyzes cholinergic neurons through inhibition of ACh synthesis. These results indicate that BrACh interacts with cholinergic receptors specifically and directly. When the incubation time was prolonged to 15 min or longer in the organ bath, BrACh (2×10^?3 M) produced irreversible blockade of the neuromuscular transmission in chick biventer cervicis and rat diaphragm preparations. The latter blockade was prevented partially by ACh (2×10^?2 M) and d-tubocurarine (3.4×10^?6 M) (25–38%) and markedly by carbachol (1×10^?4 M) and decamethonium (6.2×10^?4 M)_(76–79%), indicating agani that BrACh binds specifically and irreversibly to the cholinergic receptor. Therefore, ¹⁴C-BrACh is recommended for use in mapping, estimation, and isolation of cholinergic receptors. In order to do such experiments, the biological preparations would have to be pretreated with cold organophosphorus compounds in order to prevent irreversible binding of BrACh to cholinesterases.     

碘化二甲基木防己碱的药物—受体相互作用研究

碘化二甲基木防己碱(Dimethyltrilobine iodide简称DTI),具有降压作用,抗心律失常作用和骨骼肌松弛作用。初步证明,DTI属非去极化型肌松剂,拮抗性质推测为竞争性拮抗。究竟是否确属竞争性拮抗,强度如何,尚待研究。为此,我们用蟾蜍腹直肌标本作了进一步研究,并与箭毒作了比较。     

Cu2+对神经肌肉接头传递的作用

Cu²⁺对间接刺激诱发大鼠隔肌的收缩及诱发小鸡颈二腹肌的收缩均产生浓度依赖性抑制作用。但Cu²⁺不影响膈神经的兴奋和传导,对直接刺激诱发膈肌收缩的抑制作用弱于间接刺激诱发膈肌收缩的抑制。Cu²⁺不影响小鸡颈二腹肌对Ach的敏感性。说明Cu²⁺主要作用于突触前膜阻滞神经肌接头的传递。Ca²⁺,L-半胱氨酸可拮抗Cu²⁺的阻滞提示Cu²⁺可能与突触前膜的SH基结合,影响Ca²⁺的跨膜内流,减少Ach的释放,阻滞神经肌接头的传递。     

The actions of aminopyridines on avian muscle

Summary The effects of 2-, 3-, and 4-aminopyridines were investigated on the isolated chick biventer cervicis nerve-muscle preparation and on nerve-free cell cultures of embryonic chick skeletal muscle. All 3 compounds reversed tubocurarine blockade and augmented twitch height in indirectly stimulated biventer cervicis preparations. 4-Aminopyridine was approximately 10 times more potent than 2-, or 3-aminopyridine. Twitch augmentation was also seen in directly stimulated preparations but to a much lesser extent. The compounds did not have significant anticholinesterase activity, nor did they have any depolarizing activity when tested on nerve-free cultured muscle fibres. At high concentrations the aminopyridines produced a maintained contracture in the biventer preparations which was enhanced by neostigmine and inhibited by tubocurarine. It is suggested that the aminopyridines facilitate neuromuscular transmission by increasing acetylcholine release in response to nerve stimulation, and that the compounds can also increase spontaneous transmitter release.     

The effect of 5-hydroxytryptamine on the chick biventer cervics muscle

The actions of 5-hydroxytryptamine have been studied in the chick biventer cervics nerve—muscle preparation. At concentrations between 2.5 × 10^?3 and 3.7 × 10^?3 M, 5HT produced a transient increase in responses to indirect stimulation, but not to direct stimulation. At higher concentrations, 5HT produced a reversible depression of twitches, which was much more marked in indirectly than in directly stimulated preparations. In a concentration range of 2.5–3.7 × 10^?3 M, 5HT increased the response to exogenous acetylcholine but reduced the response to carbachol. After pretreatment with neostigmine, 5HT inhibited responses to both acetylcholine and carbachol. It is suggested that the facilitatory effects of 5HT are due to its anticholinesterase activity. The blocking actions of 5HT are thought to be curare-like. In addition, irreversible toxic effects on the muscle preparations were found after repeated exposures to high concentrations of 5HT.     

Interactions between tetraethylammonium and methohexitone at the chick neuromuscular junction: Experiments with the moving fluid electrode technique

The effect of methohexitone on the depolarization and contracture responses produced by tetraethylammonium (TEA), acetylcholine (ACh) and repetitive indirect stimulation were investigated, using the moving fluid electrode technique, in the chick biventer cervicis (BVC) nerve muscle preparation. TEA (4.8 × 10^?4?4.8 × 10^?2 M) produced contracture and depolarization responses which were concn-dependent. These responses were potentiated by methohexitone (8.8 × 10^?5 M). The mean ED₅₀S for the contracture responses in the control Krebs solution and with methohexitone were (mean ± S.E.M.) 6.5 ± 0.03 × 10^?3 M and 1.3 ± 0.04 × 10^?3 M (N = 6) respectively. The mean ED₅₀S for the depolarizations were (mean ± S.E.M.) 5.9 ± 0.1 × 10^?3 and 1.5 ± 0.06 × 10^?3 M (N = 6) respectively. ACh (5.5 × 10^?6?1.1 × 10^?2 M) produced contracture and depolarization responses which were concn-dependent. These responses were reduced by methohexitone (8.8 × 10^?5 M). The mean ED₅₀S for the contracture responses in the control Krebs solution and with methohexitone were (mean ± S.E.M. 2.4 ± 0.21 × 10^?4 and 2.3 ± 0.1 × 10^?3 M (N = 6) respectively. The mean (± S.E.M.) ED₅₀S for the depolarizations were 8.4 ± 0.33 × 10^?4 and 3.7 ± 0.14 × 10^?3 M (N = 6), respectively. Repetitive indirect stimulation, at 1–20 Hz, produced contraction and depolarization responses which were frequency-dependent. These responses were slightly potentiated by methohexitone (8.8 × 10^?5 M). The mean (± S.E.M.) frequency₅₀S for the contractions produced in the control Krebs solution and with methohexitone were 9.2 ± 0.1 and 8.5 ± 0.2 Hz (N = 6) respectively. The mean frequency₅₀S for the depolarizations were (mean ± S.E.M.) 7.2 ± 0.1 and 5.8 ± 0.19 Hz (N = 6) respectively. It is concluded that TEA may have a direct post-synaptic action, in addition to releasing ACh from the presynaptic nerve terminals. TEA produces more contracture tension than does ACh for a given level of membrane depolarization. Methohexitone, non-competitively, reduces the responses produced by applied ACh whereas it potentiates those produced by TEA and repetitive nerve stimulation.     

眼镜王蛇(Ophaiophagus hannah Cantor)毒的分离及毒性组分的研究

眼镜王蛇毒用CM-C11柱层析,醋酸铵缓冲液洗脱,分出15个蛋白组分,其中组分Ⅷ、Ⅸ、Ⅻ和ⅩⅢ为毒性较大的致死组分。实验证明眼镜王蛇全毒及四个毒性组分都不具有心脏毒及突触前神经毒活性。它们阻断小鸡颈二腹肌神经肌标本对间接刺激及对外源性乙酰胆碱的反应;神经肌传递阻滞后,标本对直接刺激及对氯化钾的反应不受影响。组分Ⅸ、Ⅻ和ⅩⅢ对神经肌传递的阻滞容易逆转,组分Ⅷ则较难逆转。这四个毒性组分均为突触后神经毒,其毒力依次为Ⅷ＞Ⅸ＞Ⅻ＞ⅩⅢ,眼镜王蛇毒的主要毒性成分是突触后神经毒。