September 8, 2009
Insects Could Replace Mice In Lab Tests
Insects could replace many lab mice used for evaluating the safety of certain drugs, researchers reported on Tuesday.
Dr. Kevin Kavanagh, from the National University of Ireland, and colleagues found that insects, such as moths, and fruit flies, could safely be used to replace mice in lab testing for drug safety.
The team showed that neutrophils "“ a type of white blood cell that are part of the immune system of mammals "“ react to infecting microbes in similar fashion to haematocytes "“ cells used to carry out a similar function in insects.
"It is now routine practice to use insect larvae to perform initial testing of new drugs and then to use mice for confirmation tests," said Kavanagh, whose team showed that both neutrophils and haematocytes produce chemicals with a similar structure which move to the surface of the cells to kill the invading microbe.
The immune cells then enclose the microbe and release enzymes to break it down.
Researchers said that the method could allow for insects to replace up to 90 percent of mice used to test new drugs.
"This method of testing is quicker, as tests with insects yield results in 48 hours whereas tests with mice usually take 4 to 6 weeks. And it is much cheaper too," Kavanagh added.
"We used insects instead of mammals for measuring how pathogenic a bacterium or fungus is, and found a very good correlation between the results in mammals and insects," Kavanagh told Reuters.
"The reason for this ... is that the innate immune system of mammals is almost 90 percent similar to that of insects."
Researchers said insects such as fruit flies, greater wax moths and a type of hawkmoth, could all be effectively used to replace mice in lab tests.
"In addition we have shown that immune cells in insects and mammals are structurally and functionally similar despite being separated by over 400 million years of evolution," said Kavanagh.
"We will continue to explore the similarities between insect and mammalian immune responses so that insects can be used as models to study different disease states in humans," he added.
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