A fundamental rule of any scientific experiment is that it must be reproducible. An experiment is reproducible when it always produces an identical result, wherever and whenever it is performed and by whichever researcher. If this is not the case, something is wrong. Either the hypothesis is wrong, or it is not demonstrable, or the method used to demonstrate it is flawed. We need to know, therefore, whether experiments on animals( including the human animal ) have this intrinsic property of reproducibility. One answer comes from research carried out at the University of Bremen, published in a paper entitled 'Die Problematik der Wirkungsschwelle in Pharmakologie und Toxikologie' (Problems of the efficacy threshold in pharmacology and toxicology). This research shows that:
1. Subjected to ionizing irradiation, young animals react differently from older ones. 3. There are major differences in the effects of tranquillizers on young versus older animals. 5. In LD-50 tests (LD= lethal dose at which 50% of the experimental animals die) carried out on rats in the evening, almost all the rats died; in those carried out in the morning, all survived. In tests done in winter, survival rates were double those recorded in the summer. Where toxic substances were administered to mice in crowded cages, nearly all died, whereas all the mice given the substance in normal cage conditions survived.
The authors of this research concluded: ‘If such minor environmental differences lead to such divergent and unforeseen results, animal experiments cannot be relied upon in the assessment of chemical substances, and it is all the more absurd to extrapolate to human medicine results that are intrinsically false.' Finally, it should be noted that the above observations were made not by anti-vivisectionists but by vivisectors themselves, who have shown, to their credit, the merit of defining the limitations of a methodology in which they had hitherto firmly believed.
「Vivisection or Science ? ―An Investigation into Testing Drugs And Safeguarding Health―」 PIETRO CROCE著 1999年 ZED BOOKS出版 9ページより引用