The presynaptic activity of huwentoxin-I, a neurotoxin from the venom of the chinese bird spider Selenocosmia huwena.

Three different types of isolated nerve-synapse preparations, guinea pig ileum, rat vas deferens and toad heart, were used to investigate the physiological activity of Huwentoxin-I, a neurotoxin from the venom of the spider Selenocosmia huwena. The twitch response of isolated guinea pig ileum induced by electrical stimulus can be inhibited by HWTX-I. After blockage, contraction of the ileum can be induced by exogenously applied acetylcholine. HWTX-I caused the inhibition of the twitch response to electrical nerve stimulation in the rat vas deferens. After the twitch was completely inhibited, noradrenaline triggered rhythmic contraction of the vas deferens. The inhibitory effect on heart of toad induced by stimulating sympathetic-vagus nerve can be reversed by HWTX-I, although exogenously applied acetylcholine still acts as an effective inhibitor. All of these results support the conclusion that HWTX-I has the presynaptic activity that effects the release of neurotransmitter from the nerve endings of both the cholinergic synapse and the adrenergic synapse.     

普罗托品松弛气管平滑肌的作用机制研究

目的　为评价普罗托品 (Pro)作为平喘药侯选者的可能性提供资料。方法　①观察不同浓度Pro对组胺、乙酰胆碱收缩的豚鼠离体气管螺旋条的舒张作用及其量效反应。②放射免疫法测定Pro对家兔气管平滑肌中环腺苷酸 (cAMP)、环鸟苷酸(cGMP)水平的影响。③高效液相色谱法检测Pro对豚鼠气管平滑肌磷酸二酯酶 (PDE)活性的影响。结果　①Pro能明显抑制组胺和乙酰胆碱引起的豚鼠离体气管条收缩 ,使其量效曲线右移 ,最大反应压低 ,pD2 ′分别为 3.11和 3.4 5。②Pro能增加家兔气管平滑肌中cAMP水平 ,而cGMP水平的变化无统计学意义。③Pro能抑制水解cAMP的PDE活性 ,但水解cGMP的PDE活性无明显降低。结论　Pro可抑制豚鼠气管平滑肌的收缩 ,其作用机制之一可能为其抑制气管平滑肌PDE活性 ,主要通过提高细胞中cAMP水平 ,进而松弛气管平滑肌     

Acetamide—45抑制组胺和乙酰甲胆碱引起的豚鼠离体气管收缩

目的:探讨新型抗变态反应药N-对氟苄基-3-[(N-4-吡啶)-乙酸胺]-吲哚-45(acetamide-45)对组胺和乙酰甲胆碱引起的豚鼠离体气管收缩的影响.方法:以acetamide-45预处理气管标本后,以累积剂量法给予组胺和乙酰甲胆碱,观察acetamide-45对组胺和乙酰甲胆碱量效曲线的影响.气管张力的变化通过换能器转变为电信号并由记录仪记录.结果:Acetamide-45(1-30μmol/L)浓度依赖地抑制组胺和乙酰甲胆碱引起的豚鼠离体气管收缩.Acetamide-45(3,10,30μmol/L)使组胺的量效曲线的最大效应下降了21％—51％,使组胺的EC_(50)值(95％可信限)分别增加到31.1(24.4—39.8),34.7(26.8-45.0)和134.4(82.2-220.0)μmol/L.另一方面,acetamide-45更有效地抑制乙酰甲胆碱引起的豚鼠离体气管收缩.结论:Acetamide-45抑制由组胶和乙酰甲胆碱引起的豚鼠离体气管收缩,提示acetamide-45的抑制作用是非特异性地作用于组胺受体或胆碱能受体.     

The effect of prophylactic anti-asthma drugs on PAF-induced airway hyperreactivity

Intravenous injection of platelet activating factor (PAF) in anesthetized guinea pigs induces non-selective airway hyperreactivity. This response to PAF was reduced in a dose-dependent manner by systemic administration of established prophylactic anti-asthma drugs (ketotifen, cromoglycate, aminophylline and glucocorticosteroids) and by competitive antagonists of PAF. These inhibitory effects could not be accounted for by antagonism of histamine (H1), serotonin or peptidoleukotrienes receptors; parasympatholytic activity; cyclo-oxygenase or lipoxygenase inhibition; mast cell stabilization; or bronchodilatation. Infusion or injection of PAF to induce airway hyperreactivity in the guinea pig may provide a prospective test for prophylactic anti-asthma drugs.     

鸭嘴花碱对豚鼠离体气管平滑肌收缩功能的影响

目的：研究鸭嘴花碱对组胺和乙酰胆碱所致气管收缩的抑制作用。方法：离体豚鼠气管条。结果：鸭嘴花碱能抑制氯化钾、乙酰胆碱、磷酸组胺所致气管平滑肌收缩，而且能使磷酸组胺、乙酰胆碱收缩气管平滑肌的量效曲线右移，并抑制最大效应，其作用为剂量依赖性。结论：鸭嘴花碱对气管平滑肌具有显著舒张作用。     

Influence of epithelium on the inhibition of melittin-induced contraction of guinea-pig isolated trachea by the potassium channel opener NIP-121.

1. We have investigated the effect of the potassium channel opener, NIP-121, on contraction elicited by melittin (a phospholipase A2 activator) in epithelium-intact and epithelium-denuded trachea isolated from guinea-pigs. The effects of NIP-121 were compared with those of isoprenaline, aminophylline and hydrocortisone. 2. In the presence of the cyclo-oxygenase inhibitor, indomethacin (5 microM), melittin (3 micrograms ml-1) caused time-dependent contraction. The melittin-induced contractile response was significantly augmented by removal of the epithelium and was concentration-dependently and completely inhibited by the phospholipase A2 (PLA2) inhibitor, p-bromophenacyl bromide (BPB 10-100 microM), and the lipoxygenase inhibitor, phenidone (10-300 microM). Similar inhibition of the melittin response by BPB (10 microM) and phenidone (10 microM) was observed in the epithelium-denuded trachea. 3. Concentration-dependent inhibition of the melittin response was induced by preincubation with NIP-121 (0.03 and 0.1 microM), isoprenaline (0.001 and 0.01 microM), aminophylline (30 and 100 microM) and hydrocortisone (100 and 300 microM). The effect of NIP-121 was abolished by glibenclamide (1 microM). 4. The inhibitory effect of NIP-121 on the melittin response was greatly reduced by removing the epithelium while that of the isoprenaline, aminophylline or hydrocortisone was not changed. 5. The inhibition of the melittin response by these drugs was similar to their inhibition of the contraction elicited by a low concentration (3 nM) of leukotriene D4 (LTD4) in the epithelium-intact trachea. Inhibition of the LTD4 response by NIP-121 was not observed in the epithelium-denuded trachea.(ABSTRACT TRUNCATED AT 250 WORDS)     

川芎嗪对几种致喘介质所致离体豚鼠气管条收缩作用的影响

观察川芎嗪对白三烯C_4、D_4、组织胺、前列腺素F_(2a)、乙酰胆碱等所致豚鼠离体气管条收缩作用的影响,发现除乙酰胆碱外,川芎嗪对其他几种致喘介质均有一定抑制作用,为非竞争性拮抗剂。本实验似可为川芎嗪的平喘作用提供了一定的理论基础。     

NIP-121 and cromakalim, potassium channel openers, preferentially suppress prostanoid-induced contraction of the guinea-pig isolated trachea.

We have investigated the relaxant effect of the potassium channel openers, NIP-121 and cromakalim, on spontaneous and spasmogen-induced tone in the isolated guinea-pig trachea. NIP-121 and cromakalim fully suppressed the spontaneous tone in a concentration-dependent manner and the maximal response was 89 and 97% of that to 1 mM aminophylline. The suppressant effect of NIP-121 (pD2 7.39) was 5 times stronger than that of cromakalim (pD2 6.69). Spontaneous tone was completely inhibited by the cyclooxygenase inhibitor, indomethacin, and partially inhibited by the thromboxane A2 (TXA2) antagonist, BM13177. In the presence of indomethacin, the contraction induced by prostaglandin (PG) F2 alpha and PGD2 was reversed by BM13177 to the same extent. NIP-121 and cromakalim reversed the contraction induced by PGF2 alpha, PGD2 and the TXA2 mimetic, U46619, and the effects were more potent than those observed on the contraction induced by leukotriene (LT) D4, LTC4, histamine and acetylcholine. The maximal relaxant responses (%) induced by NIP-121 and cromakalim were 97 and 96 for PGF2 alpha, 94 and 87 for PGD2, 94 and 93 for U46619, 69 and 69 for LTD4, 75 and 58 for LTC4, 73 and 61 for histamine and 1 and 16 for acetylcholine, respectively. The relaxant effect of NIP-121 on responses to these spasmogens (pD2 7.35 for PGF2 alpha, 7.40 for PGD2, 7.31 for U46619, 7.28 for LTD4, 7.09 for LTC4, and 7.15 for histamine) was about 10-20 times stronger than the effect of cromakalim (pD2 6.23 for PGF2 alpha, 6.04 for PGD2, 6.20 for U46619, 6.01 for LTD4, 5.82 for LTC4 and 5.88 for histamine).(ABSTRACT TRUNCATED AT 250 WORDS)     

当归成分藁本内酯平喘作用的实验研究

从甘肃岷县当归挥发油中,分离出一淡黄色油性物质,鉴定为藁本内酯,实验证明有明显的平喘作用。给豚鼠ip 0.14 ml/kg能缓解组织胺与乙酰胆碱的致喘反应,其效力约与氨茶碱50 mg/kg相仿。在豚鼠肺溢流实验,ⅳ藁本内酯0.08 ml/kg能对抗组织胺2～10 μg/kg所引起的支气管收缩。藁本内酯不仅对豚鼠离体气管条有松弛作用,而且对乙酰胆碱、组织胺以及氯化钡引起的气管平滑肌痉挛收缩,有明显的解痉作用。上述作用不能被心得安所阻断。藁本内酯对豚鼠肺、肠组织内cAMP及cGMP的含量均无明显影响。     

Modulation of cholinergic neurotransmission in guinea-pig airways by opioids.

1. Opioid receptors have been localised on sensory fibres in the vagus nerve and opioids have previously been shown to inhibit non-adrenergic, non-cholinergic (NANC) neurotransmission in guinea-pig bronchi in vitro and in vivo. We have now investigated whether an inhibitory effect could be demonstrated on cholinergic neurotransmission. 2. Electrical field stimulation (EFS) (8 Hz, 0.5 ms, 40 V for 20 s) produced only a rapid, cholinergic response in the upper trachea but in the lower trachea and main bronchi a cholinergic response which was atropine-sensitive and a longer lasting NANC contraction that was atropine-insensitive was demonstrated. This slow contraction could be blocked by tetrodotoxin and capsaicin pretreatment. 3. [D-Ala2, NMePhe4, Gly-ol5]enkephalin (DAMGO), a selective mu-opioid receptor agonist, inhibited the cholinergic response to EFS at 8 Hz in a dose-dependent manner in main bronchi (IC50 = 113 nM with a maximal inhibition of 35.7 +/- 5.6% 10 microM, n = 5). In the lower trachea, DAMGO inhibited the cholinergic response to a similar extent (inhibition of 35.8 +/- 3.5% at 10 microM, n = 5). However, DAMGO had no effect on the contractile response to exogenously applied acetylcholine in the main bronchi. By contrast, opioids had no inhibitory effect on cholinergic neurotransmission in the upper trachea. DAMGO (1 microM) inhibited the cholinergic response to EFS in a frequency-dependent manner in the main bronchi with greater inhibition at lower frequencies of stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of three novel K+ channel openers, cromakalim, pinacidil and nicorandil on allergic reaction and experimental asthma.

The anti-allergic and anti-asthmatic activities of three potassium (K+) channel openers, cromakalim, pinacidil, and nicorandil, were investigated. 1) Forty-eight-hour homologous passive cutaneous anaphylaxis (PCA) in mice was not affected by cromakalim, pinacidil, or nicorandil. Ketotifen significantly inhibited the reaction. 2) Antigen-induced histamine release from sensitized guinea pig lung tissue was not affected by cromakalim, pinacidil or nicorandil (except for 10(-4) M nicorandil). Salbutamol inhibited the release of histamine. 3) Histamine, serotonin and LTC4-induced vasculitis in rat back skin was not affected by any of these three K+ channel openers. 4) Antigen-induced constriction of isolated sensitized guinea pig tracheal muscle was relaxed by each of the K+ channel openers. 5) Constrictions of isolated guinea pig tracheal muscle caused by high potassium, histamine, LTC4, or U-46619 were clearly relaxed by each of the three K+ channel openers. 6) Increases of airway resistance caused by histamine, LTD4, or U-46619 in guinea pigs in vivo were inhibited by administration of each of the three K+ channel openers. 7) Experimental asthma caused by the IgE antibody and antigen system in guinea pigs was inhibited by each of the three K+ channel openers.     

葛缕酮的气道扩张作用和呼吸道抗过敏作用

目的观察留兰香油中葛缕酮的气道扩张作用和对呼吸道介质的影响。方法用豚鼠药物引喘法、豚鼠离体气管片法、致敏豚鼠肺组织ＳＲＳ Ａ释放和拮抗ＳＲＳ Ａ、致敏豚鼠离体气管Ｓｃｈｕｌｔｚ Ｄａｌｅ反应法检测。结果葛缕酮对豚鼠药物性哮喘具有保护作用,灌胃给药延长５０％剂量为７６ｍｇ·ｋｇ－１,气雾给药为６３ｇ·Ｌ－１;对豚鼠离体气管有直接松弛作用,ｐＤ２值为４２７±００８,并有抗氨甲酰胆碱作用;能抑制致敏豚鼠肺组织ＳＲＳ Ａ的释放,ＩＣ５０为１８ｍｇ·Ｌ－１,拮抗ＳＲＳ Ａ收缩回肠的ＩＣ５０为２７ｍｇ·Ｌ－１,并能抑制致敏豚鼠离体气管的Ｓｃｈｕｌｔｚ Ｄａｌｅ反应。结论葛缕酮具有气道扩张作用和呼吸道抗过敏作用。     

肺清颗粒药效学作用初探

目的研究肺清颗粒镇咳、祛痰、平喘和抗菌作用。方法以小鼠氨水引咳法、小鼠枸橼酸引咳法和豚鼠枸橼酸引咳法观察其镇咳作用;以小鼠酚红排泌法观察其祛痰作用;以豚鼠乙酰胆碱-组胺引喘法和豚鼠离体气管条试验观察其平喘作用;采用抑菌圈测定法观察肺清颗粒的体外抑菌作用。结果肺清颗粒对小鼠氨水引咳具有显著的镇咳作用,对乙酰胆碱-组胺所致的豚鼠哮喘具有显著的平喘作用;对组胺或乙酰胆碱致痉的豚鼠离体气管条有显著的解痉作用;体外对金黄色葡萄球菌、肺炎球菌和肺炎克雷伯菌有一定的抑制作用。结论肺清颗粒对实验动物具有显著的镇咳、祛痰及平喘作用,并具有一定的抗菌作用。     

佛司可林类化合物对离体豚鼠气管条舒张作用的研究

目的研究佛司可林、异佛司可林、佛司可林G、J、A、I对磷酸组胺(His)、氯化乙酰胆碱(ACh)引起的离体豚鼠气管条收缩作用的影响。方法取豚鼠气管制成螺旋状气管条,用磷酸组胺、氯化乙酰胆碱诱发气管条收缩,按累积剂量法加入系列浓度的佛司可林、异佛司可林、佛司可林G、J、A、I,观察其对气管条收缩反应的舒张作用,记录各累积浓度下的量效曲线,计算解痉百分率。结果异佛司可林、佛司可林均能明显舒张由His、ACh引起的离体豚鼠气管条的收缩(P<0.01)。佛司可林G、J、A、I均能舒张由His引起的离体豚鼠气管条的收缩(P<0.01)。且随着剂量的增加,舒张作用也有所增强。结论佛司可林、异佛司可林、佛司可林G、J、A、I对His或ACh引起的离体豚鼠气管条的收缩均具有舒张作用。     

MCI-826 is a potent and selective antagonist of peptide leukotrienes (p-LTs) and has characteristics distinctive from those of FPL 55712.

Antagonistic effects of a newly synthesized compound, (E)-2,2-diethyl-3'-[2-[2-(4-isopropyl)thiazolyl]ethenyl]succinanilic+ ++ acid sodium salt (MCI-826) on the contraction of the isolated guinea pig trachea and human bronchus induced by various agonists including peptide leukotrienes (p-LTs), histamine, acetylcholine (ACh), prostaglandin (PG) D2 and others were investigated and compared with the effects of a p-LT antagonist, FPL 55712, in some experiments. MCI-826 potently antagonized LTD4- and LTE4-induced contractions at extremely low concentrations in the isolated guinea pig trachea with pA2 values of 8.3 and 8.9, respectively, on a molar basis. These values indicated that MCI-826 is over 100 times stronger than FPL 55712. Similarly, MCI-826 at 10(-8) g/ml (2.4 x 10(-8) M) markedly antagonized LTD4-induced contractions of the isolated human bronchus. Although FPL 55712 fairly inhibited the 10(-9) g/ml LTC4-induced contraction of the isolated guinea pig trachea, MCI-826 had little effect on the contraction at high concentrations like 3 x 10(-6) g/ml (7.1 x 10(-6) M). MCI-826 modestly affected the other agonist-induced contractions and the resting tonus of the isolated guinea pig trachea at 10(-6) g/ml (2.4 x 10(-6) M) or higher concentrations, but FPL 55712 caused fair inhibition of some of those contractions and gradually lowered the resting tonus with time. These results indicate that MCI-826 is a highly potent and selective antagonist of LTD4 and LTE4 and can be a useful tool for biological and pharmacological experiments on p-LTs.     

硫酸寡糖对豚鼠气管平滑肌的作用

目的 观察硫酸寡糖对组胺(His)、乙酰胆碱(Ach)引起的正常豚鼠离体气管平滑肌收缩的影响、对卵白蛋白(OVA)致敏豚鼠离体气管平滑肌受到OVA攻击时引起收缩的影响及对吸入His引起的正常整体豚鼠哮喘的影响。方法 采用豚鼠离体气管片法、致敏豚鼠离体气管Schultz-Dale法和整体动物引喘法。结果 硫酸寡糖能显著抑制His引起的正常豚鼠离体气管平滑肌收缩,但对Ach引起的正常豚鼠离体气管平滑肌收缩无显著抑制作用;能显著抑制OVA诱发的致敏豚鼠离体气管平滑肌的收缩;能显著延长His引喘潜伏期,使抽搐动物数减少。结论 硫酸寡糖具有抗His、抗过敏和平喘作用。     

Inhibitory effect of the newly synthesized pyridazinone derivative NZ-107 on bronchoconstriction induced by slow reacting substance of anaphylaxis in the guinea pig

We have investigated the effect of a newly synthesized compound NZ-107, 4-bromo-5-(3-ethoxy-4-methoxybenzylamino)-3(2H)-pyridazinone, on bronchoconstriction induced by slow reacting substance of anaphylaxis (SRS-A) in the guinea pig. Orally administered NZ-107 (10 mg/kg, 2 hr) inhibited antigen-induced SRS-A-mediated bronchoconstriction in sensitized guinea pigs. NZ-107 (2 mg/kg, i.v., 1 min) prevented the antigen-induced response about as well as the SRS-A antagonist FPL-55712 and rapidly reversed it. This rapid reversal by NZ-107 but not FPL-55712 also appeared with the leukotriene (LT) D4-induced contraction of the isolated trachea. NZ-107 more selectively inhibited the LTD4 response than those of histamine, acetylcholine and KCl. Compared to FPL-55712, NZ-107 was one-fifteenth less potent in inhibiting the LTD4 response, but two-fold more potent in inhibiting the LTC4 response. NZ-107 inhibited the LTD4 response of the trachea 10-fold more potently than that of the ileum (-log IC50: trachea 5.61, ileum 4.56). The combination of NZ-107 (1 microM) with the beta-agonist isoproterenol had no synergistic effect on the LTD4 response, but those of theophylline and papaverine had large effects. From these results, NZ-107 is a selective inhibitor of the SRS-A response and may be useful in the therapy of bronchial asthma and other diseases in which the LTs are thought to be involved.     

The extract from Nandina domestica THUNBERG inhibits histamine- and serotonin-induced contraction in isolated guinea pig trachea

Although the fruit of Nandina domestica THUNBERG (ND) has been used to treat respiratory disorders such as coughing and breathing difficulty in Japan for many years, very little is known about mechanisms underlying its action. In the present study, we investigated effects of the crude extract from ND (NDE) and one of its constituents, nantenine, on contractile responses in isolated guinea pig tracheal ring preparations. In normal experimental condition, guinea pig trachea remained tonically contracted during the resting state, and addition of NDE (1 mg/ml) caused a relaxation of tracheal smooth muscles, but had little effect on the responsiveness of trachea to acetylcholine. The basal, tonic contraction was abolished by the presence of atropine and indomethacin. In this condition, NDE at 0.1-1 mg/ml inhibited histamine-induced contraction in both competitive and non-competitive manners. NDE at 0.01-1 mg/ml inhibited serotonin-induced contraction in a competitive manner. Nantenine (2-20 microM) did not affect histamine-induced contraction, and slightly inhibited serotonin-induced contraction. These results suggest that NDE has inhibitory effects on tracheal smooth muscle contraction, and nantenine cannot account solely for this effect of NDE.     

Pharmacological activities of Lantana trifolia on isolated guinea pig trachea and rat phrenic nerve diaphragm

A methanol extract of L. trifolia produced bronchodilation of isolated guinea pig trachea comparable to that of salbutamol. The plant extract reduced bronchoconstriction induced by histamine, 5-HT and acetylcholine on isolated guinea pig trachea. Physostigmine failed to inhibit neuromuscular blocking activity of the extract on rat phrenic nerve diaphragm.     

Effects of lipopolysaccharide on epithelium-dependent relaxation in coaxial bioassay

This study investigated the effects of airway inflammation elicited by intraperitoneal and intratracheal lipopolysaccharide administration to guinea pigs on the activity of tracheal epithelium-derived relaxant factor (EpDRF). Acetylcholine induced epithelium-dependent relaxation in precontracted rat anococygeus muscle placed in guinea pig trachea (coaxial bioassay). Indomethacin, N-nitro-l-arginine methyl ester, aminoguanidine and l-canavanine did not alter this relaxation excluding the role of prostaglandins and nitric oxide (NO). Intraperitoneal lipopolysaccharide potentiated the acetylcholine response, which was reversed by aminoguanidine and l-canavanine while intratracheal lipopolysaccharide inhibited acetylcholine-induced relaxation. Lipopolysaccharide pretreatments did not cause epithelial damage but induced inflammatory cell infiltration. These results suggested that systemic lipopolysaccharide administration did not alter the EpDRF response but resulted in NO synthase induction, thus NO participated in relaxation to acetylcholine in coaxial bioassay system. On the other hand, airway inflammation induced by intratracheal lipopolysaccharide attenuated the synthesis/release of EpDRF without altering the epithelium morphology.