An Introduction to the Avermectins
New Zealand Veterinary JournalPublished 1 October 1981
William C. Campbell
Citations73
SJR quartileQ2
SJR score0.34
SNIP0.58
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TL;DR
The avermectins appear to paralyze nematodes and arthropods by potentiating the presynaptic release of gamma-aminobutyric acid, thereby blocking post-synaptic transmission of nerve impulses.
Abstract
Abstract The avermectins are macrocyclic lactones with exceptional potency and spectrum of activity against nematode and arthropod parasites. They are produced by a new species of actinomycete, Streptomyces avermitilis. They are active when given orally or parenterally, at dosages of a fraction of a milligram per kilogram, against many immature and mature nematode and arthropod parasites of sheep, cattle, dogs, horses and swine. The avermectins appear to paralyze nematodes and arthropods by potentiating the presynaptic release of gamma-aminobutyric acid, thereby blocking post-synaptic transmission of nerve impulses. A chemically modified derivative, 22,23-dihydroavermectin B1, known generically as ivermectin, has been selected for development.
Keywords
Immunology and MicrobiologyAgricultural and Biological SciencesMedicine
Antimicrobial Agents and ChemotherapyAvermectins, New Family of Potent Anthelmintic Agents: Producing Organism and Fermentation
940 Citations1979Richard W. Burg, Brinton M. Miller +13 more
The avermectins are a complex of chemically related agents which exhibit extraordinarily potent anthelmintic activity and are produced by a novel species of actinomycete, NRRL 8165, which is named Streptomyces avermitilis.
Antimicrobial Agents and ChemotherapyAvermectins, New Family of Potent Anthelmintic Agents: Efficacy of the B <sub>1a</sub> Component
324 Citations1979J. R. Egerton, D.A. Ostlind +6 more
The avermectin B1a would appear to have unprecedented potency and spectrum of biological activity in relation to ruminant parasites.
Journal of Medicinal ChemistryIvermectin, a new broad-spectrum antiparasitic agent
322 Citations1980John C. Chabala, Helmut Mrozik +7 more
In conclusion, ivermectin B1 was shown to be a highly effective drug for the treatment of a wide variety of metazoan parasitic diseases in animals.
Proceedings of the National Academy of SciencesAvermectin B1a irreversibly blocks postsynaptic potentials at the lobster neuromuscular junction by reducing muscle membrane resistance.
195 Citations1979L C Fritz, C C Wang +1 more
It is hypothesized that the reduction in excitatory postsynaptic potentials after avermectin B1a treatment is caused solely by reduction in membrane resistance; additional experiments suggest that the reduced membrane resistance is due to the opening of membrane Cl- channels, perhaps including those regulated by gamma-aminobutyric acid at the inhibitory synapse.
Proceedings of the National Academy of SciencesAvermectin B1a, a paralyzing anthelmintic that affects interneurons and inhibitory motoneurons in Ascaris.
165 Citations1980Ira S. Kass, C. C. Wang +2 more
Using selective stimulation techniques, it is shown that AVM blocks transmission between interneuron(s) and excitatory motorneurons in the ventral nerve cord of Ascaris, providing an explanation of how AVM may cause paralysis of nematodes.
Journal of NeurochemistryStudies on the Mechanism of Action of Avermectin B<sub>1</sub>a: Stimulation of Release of γ‐Aminobutyric Acid from Brain Synaptosomes
115 Citations1980Sheng‐Shung Pong, Ching C. Wang +1 more
A good correlation between antiparasitic activity and γ‐aminobutyric acid‐releasing activity has been found among various derivatives of avermectin B1a, which suggests that the ability of the drug to release this neurotransmitter may be the basis of its antiparAsitic action.
British Veterinary Journal22, 23–Dihydroavermectin B 1 , A New Broad-Spectrum Antiparasitic Agent
83 Citations1980J. R. Egerton, Jerome Birnbaum +8 more
22,23-dihydroavermectin B1 has been selected for development as a unique, potent agent with utility against nematode, arachnid and insect parasites of domestic animals.
Veterinary ParasitologyThe anthelmintic efficacy of ivermectin in experimentally infected cattle
62 Citations1981J. R. Egerton, C.H. Eary +1 more
The dosage expected to remove 95% of the nematodes by each route of administration against the various developmental stages of each species of parasite was calculated by methods of linear regression to choose dose levels to be used in subsequent developmental field trials.
Veterinary ParasitologyThe antiparasitic activity of ivermectin in horses
46 Citations1981J. R. Egerton, E. S. Brokken +4 more
Analysis of the dose response curves obtained for the nematode and larval dipteran parasites found in these naturally infected horses suggests that a parenteral dose of 0.2 mg/kg ivermectin would produce 95% or more removal of these parasites.
PubMedEfficacy of Ivermectin against Dirofilaria immitis larvae in dogs 31, 60, and 90 days after injection.
36 Citations1980L. S. Blair, William C. Campbell
Ivermectin, given as a single oral dose of 0.05 mg/kg, prevented the maturation of Dirofilaria immitis in dogs if given at 31 or 60 days after infection, when treatment was delayed 90 days after injection.
Parasite ImmunologyImmunization of ferrets against Diroflaria immitis by means of chemically abbreviated infections
31 Citations1981Lyndia Slayton Blair, William C. Campbell
Ferrets were exposed to two successive inoculations with 30 third‐stage larvae of the canine heartworm Dirofilaria immitis, the inoculations being approximately 5 months apart, and four ferrets that survived this protracted experimentation were entirely free of heartworm while the other two had only a single female worm each.
Journal of HelminthologyEfficacy of Avermectins against <i>Dirofilaria immitis</i> in dogs
25 Citations1978William C. Campbell, L. S. Blair
An attempt to demonstrate similar efficacy in dogs, together with preliminary tests of avermectins against the adults and microfilariae of D. immitis is reported.
PubMedEfficacy of avermectin B1a against microfilariae of Dirofilaria immitis.
22 Citations1979Blair Ls, Campbell Wc
Avermectin B1a given at a dose level of 0.05 or 0.1 mg/kg of body weight caused rapid removal of Dirofilaria immitis microfilariae from the blood of dogs with heartworm infections.
Journal of HelminthologyEfficacy of Avermectins against <i>Ancylostoma caninum</i> in dogs
20 Citations1978Lyndia Slayton Blair, William C. Campbell
The efficacy of avermectins Bia and B2a in experimental infections of Ancylostoma caninum in dogs is reported and it is found that dosages of 0.015 mg/kg, or more, were fully effective against adult A.Caninum.
American Journal of Veterinary ResearchEfficacy of Ivermectin Against Dirofilaria immitis Larvae in Dogs 31, 60, and 90 Days After Infection
15 Citations1980Lyndia Slayton Blair, William C. Campbell
Ivermectin, given as a single oral dose of 0.05 mg/kg, prevented the maturation of Dirofilaria immitis in dogs if given at 31 or 60 days after infection if given at 31 or 60 days after infection.
PubMedTreatment of psoroptic mange with avermectins.
14 Citations1980Wilkins Ca, Conroy Ja +3 more
Good control of Psoroptes cuniculi was achieved in rabbits treated with various avermectin analogues by topical application or by subcutaneous injection of the 22,23-dihydroavermectins B1.
Journal of HelminthologyEfficacy of avermectins against <i>Trichinella spiralis</i> in mice
13 Citations1979William C. Campbell, L. S. Blair +1 more
A comparison study of the protein content of the serum and intestinal mucus of sheep with reference to the histology of the gut and immunologicai response to Oesophagostomum columbianum infections and the effect of cortisone upon Ancylostoma caninum infection in albino mice.
American Journal of Veterinary ResearchTreatment of Psoroptic Mange with Avermectins
5 Citations1980C. A. Wilkins, J. A. Conroy +4 more