- guardian.co.uk, Monday July 21 2008 10.14 BST
A technique that allows experiments to be carried out on cow eyes thrown away by abattoirs could lead to thousands fewer rabbits being used in scientific research each year.
The technique involves applying a chemical mixture that mimics tears to the surface of part of the eye. This preserves the eyes for up to two weeks, allowing scientists to use them to test new treatments for diseases and chemical burns as well as to find out whether novel chemicals are safe – without testing them on live animals.
The news comes on the day the Home Office is due to announce the latest figures on the number of animals used in experiments in Great Britain. Scientists expect the total number of procedures carried out to have grown by around 2% in 2007 from 3.01m the previous year. In 2006, mice, rats and other rodents accounted for 83% of the total. Researchers expect the number of rodents used in experiments to grow in 2007 because of the continued increase in research on genetically modified mice.
"The figures have been going up one to two per cent per annum for five to six years," said Dr Simon Festing, director of the Research Defence Society, which monitors animal experimentation. "It's clear that's going to continue because there is no question that the number of GM mice continues to go up at that level." His estimate is based on monitoring the information sent to the Home Office by universities and academic institutions that do the majority of animal research.
The new technique using waste cow and sheep eyes has the potential to reduce the numbers of a particularly emotive procedure: testing the toxicity of substances by squirting them into animals' eyes. Typically rabbits are used in these experiments.
Dr Nigel Fullwood at Lancaster University and his team are in the process of validating the technique as a replacement for a range of experiments. "The model has literally hundreds of applications," he said. "We hope it will at least significantly replace some of the animal experimentation that is carried out on, for example, rabbits at the moment." Ultimately, he believes thousands of procedures currently done on live animals will not be necessary.
The raw material for Fullwood's technique is cow eyes that he buys from his local abattoir at a pound each. "The eyes are literally thrown away. They are trash," he said. The treatment of the eyes is adapted from methods that were originally developed to preserve human corneas prior to transplant. His team is now validating the preserved corneas as alternatives for various different experimental techniques.
In his latest paper, to be published in the journal Investigative Ophthalmology and Visual Science, his team has showed that it is possible to introduce new genes into the cells. This is a promising method for preventing rejection of human cornea transplants – a technique that previously would have involved live animals to test.
Fullwood is also working to validate the preserved corneas as a replacement for toxicity tests. "We are working towards it but it is literally going to take us years. The regulatory hurdles are really quite significant," he said. Another advantage is that students can train on the preserved corneas without harming live animals. "You can let them loose on this system because it doesn't matter if they hack it apart and destroy it," he said.
Fullwood's research is publicly funded via the National Centre for the Replacement, Refinement and Reduction of Animals in Research.
Prof Colin Blakemore of Oxford University, the former head of the Medical Research Council, said that there was now a "substantially different climate" of public opinion about animal research compared with five years ago. He wants to see a less shrill and more constructive debate on the issue and is trying to foster contact between scientists and groups such as the British Union for the Abolition of Vivisection that oppose animal testing. "In terms of the more nuanced debate I've talked about before, if ever we are going to do that now is the time," he said. He no longer works with live animals himself.
In 2006, researchers in Great Britain performed 3.01m procedures on live animals. Eighty-three per cent were on rodents, 9% were on fish and 4% were on birds. Monkeys were used in 4,200 procedures, down by 10% on the previous year.
