Bowen J M, Vitayavirasak B
College of Veterinary Medicine, University of Georgia, Athens, GA 30602-7371, USA.
Vet Res Commun. 2008 Mar;32(3):231-41. doi: 10.1007/s11259-007-9022-x. Epub 2007 Sep 25.
Effects of a variety of compounds on spontaneous contractile activity of whole, intact, adult canine heartworms (HW), which had been maintained in culture, were evaluated to improve understanding of the pharmacological sensitivities of this parasitic nematode. Acetylcholine, pilocarpine, imidazole, levamisole, and DL-tetramisole caused spastic paralysis. Gamma-aminobutyrate (GABA), the GABA-mimetic muscimol, the GABA amino transferase inhibitor 3-mercaptopropionic acid, fenthion, ketamine, levodopa, and salinomycin caused flaccid paralysis. Atropine and monensin had inhibitory effects. Neostigmine, the neuromuscular blocking agents decamethonium, succinylcholine, and D-tubocurarine, and the aminergic agents epinephrine, norepinephrine, and serotonin had little or no effect on contractile activity. Thiacetarsamide had a nonreversible, slow onset, inhibitory effect on contractile activity. Occurrence of spastic or flaccid paralysis was not correlated with gender or culture age and was never associated with the same compound. Submaximal stimulatory or inhibitory responses paralleled the type of maximal responses (spastic or flaccid paralysis) for most compounds. Concentration variations producing maximal effects suggested considerable variation in individual preparation sensitivity, which did not appear to involve cuticle defects or time in culture. Difference in gender sensitivity was noted only for levamisole, which caused greater stimulation of contractile activity in males than in females.
为了更好地了解这种寄生线虫的药理敏感性，对多种化合物对培养的完整成年犬心丝虫（HW）自发收缩活性的影响进行了评估。乙酰胆碱、毛果芸香碱、咪唑、左旋咪唑和DL-四咪唑可引起痉挛性麻痹。γ-氨基丁酸（GABA）、GABA模拟物蝇蕈醇、GABA氨基转移酶抑制剂3-巯基丙酸、倍硫磷、氯胺酮、左旋多巴和盐霉素可引起弛缓性麻痹。阿托品和莫能菌素具有抑制作用。新斯的明、神经肌肉阻滞剂十烃季铵、琥珀酰胆碱和筒箭毒碱，以及胺能药物肾上腺素、去甲肾上腺素和5-羟色胺对收缩活性几乎没有影响或没有影响。硫乙酰胂胺对收缩活性具有不可逆的、起效缓慢的抑制作用。痉挛性或弛缓性麻痹的发生与性别或培养时间无关，且从未与同一种化合物相关。大多数化合物的亚最大刺激或抑制反应与最大反应类型（痉挛性或弛缓性麻痹）相似。产生最大效应的浓度变化表明个体制剂敏感性存在相当大的差异，这似乎不涉及角质层缺陷或培养时间。仅在左旋咪唑方面观察到性别敏感性差异，左旋咪唑对雄性收缩活性的刺激作用大于雌性。
