Regional Parasite Research Laboratory, ARS, USDA, P. O. Box 952, 36830, Auburn, Alabama.
J Chem Ecol. 1986 Jan;12(1):147-54. doi: 10.1007/BF01045598.
Ingestion by the nematodeTrichostrongylus colubriformis was stimulated by serotonin, histamine, and dopamine. Immune serum inhibited feeding by both sexes while octopamine depressed feeding by only male nematodes. However, the combined influence of these excitatory and inhibitory stimuli is unknown. Feeding in vitro by both sexes of the nematodeT. colubriformis was similar in millimolar ratios of histamine and dopamine or histamine and serotonin, but not dopamine and serotonin. Feeding by nematodes that was stimulated by histamine, dopamine, and serotonin was decreased by subsequent exposure to octopamine. Conversely, elevated concentrations of histamine, dopamine, and serotonin decreased the inhibitory action of octopamine on helminth ingestion in vitro. Doses of immune serum also decreased the stimulated feeding of nematodes that was induced by histamine, dopamine or serotonin. However, the addition of elevated concentrations of these biogenic amines to immune serum reversed the inhibitory effect. The feeding activity of nematodes may represent a summation of the inhibitory and excitatory stimuli that occur in the chemical environment of the helminth.
类圆线虫的摄食受 5-羟色胺、组胺和多巴胺的刺激。免疫血清抑制雌雄两性的摄食，而章鱼胺则仅抑制雄性线虫的摄食。然而，这些兴奋和抑制性刺激的综合影响尚不清楚。在体外，雌雄两性类圆线虫的摄食在组胺和多巴胺或组胺和 5-羟色胺的毫摩尔比例上相似，但在多巴胺和 5-羟色胺的比例上则不同。由组胺、多巴胺和 5-羟色胺刺激的线虫摄食，随后暴露于章鱼胺时会减少。相反，组胺、多巴胺和 5-羟色胺浓度的升高会降低章鱼胺对体外寄生虫摄食的抑制作用。免疫血清的剂量也会降低由组胺、多巴胺或 5-羟色胺诱导的线虫刺激摄食。然而，将这些生物胺的浓度升高添加到免疫血清中会逆转其抑制作用。线虫的摄食活性可能代表了寄生虫化学环境中发生的抑制和兴奋刺激的总和。
