Pharmacological evaluation of contractile activity of the dog heartworm Dirofilaria immitis.

Article date: 2007/9/28

PubMed ID: 2852396

Journal name: Veterinary research communications (ISSN: 0165-7380)


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.

Author List: Bowen J M, Vitayavirasak B

Publication Types: Journal Article; Research Support, Non-U.S. Gov't

Article Date: 2007/09/25

Substances mentioned in the article: Enzyme Inhibitors; Filaricides; Ionophores; Neurotransmitter Agents; Peripheral Nervous System Agents; Arsenamide;

Mesh terms: Animals; Arsenamide/pharmacology; Dirofilaria immitis/drug effects; Dirofilariasis/parasitology; Dog Diseases/parasitology; Dogs; Enzyme Inhibitors/pharmacology; Female; Filaricides/pharmacology; Ionophores/pharmacology; Male; Muscle Contraction/drug effects; Neurotransmitter Agents/pharmacology; Parasitic Sensitivity Tests/veterinary; Peripheral Nervous System Agents/pharmacology; Sex Factors; Time Factors;

Citations: - 14746979

2852396.txt · Last modified: 2018/11/20 14:25 (external edit)