Reinvestigation of the Sex "Discrimination" in Animal Experiment

       Biomedicine has always been a world dominated by men, which is not only reflected in the vast majority of researchers engaged in biomedical research, but also in the laboratory animals they use. This number far exceeds that of women.

   It is well known that there are usually significant differences between men and women both physically and psychologically. Therefore, clinical trials based only on men usually bring higher risks to women. Similarly, it is questionable whether the experimental results obtained in male-only animal experiments are female. For more information, see "Sex Discrimination in Animal Experiments" here.

   In 2011, Annaliese K. Beery and Irving Zucker of the University of California, Berkeley published an article concerning the statistical analysis of the sex distribution of experimental animals used in neuroscience and biological behavior research in biomedical research. They selected 34 biomedical journals, including "Nature" and "Science", to study the gender label of experimental animals used in 10 fields (including neurobiology, immunology and reproductive biology) in papers published in 2009. done. The results showed that only 28% of animal studies indicated the use of both male and female laboratory animals. Unfortunately, all disciplines like to use male animals except for reproductive biology. Among them, the ratio of males to females reached 5.5:1 and 5:1 respectively. In neurobiology and pharmacology experiments, male animals have the most obvious preference. In another similar analysis of 1,200 neuroscience papers published between 2011 and 2012, only 24% of animal experiments using female laboratory animals yielded the same results.

   The issue of gender "discrimination" in animal experiments is so prominent that it has attracted the attention of the scientific community. Health Canada and the National Institutes of Health have stated that there is no "special reason" that single-sex experiments must be used to complete the experiment, and the impact of gender factors on animal research must be considered. Unless there are "special reasons", we will continue to ask applicants for projects funded by them to apply for the project.

   It has been 10 years since the last survey. What happened to sex discrimination in animal experiments? Nicole (for example, Northwestern University School of Medicine) continues to use literature from 9 biological disciplines from 34 journals surveyed in 2009 to conduct new statistical analyses on this issue. Sampling results show that 49% (n = 356) of research papers in 2019 used both male and female experimental animals, a significant increase from 28% (n = 232) in 2009. I'm. Among them, the proportion of neuroscience research papers showing male and female experimental animals increased from 29% in 2009 to 63% in 2019, and the proportion of immunology research papers increased from 16% in 2009 to 46% in 2019. Increase, maximum increase. Two subjects.

  Overall (all 9 disciplines), the proportion of research involving gender has increased significantly, while the proportion of individual gender used for data analysis has not increased, but has declined. I'm. A 2009 study found that 50% of animal studies, including gender, consisted of separate male and female laboratory animals for statistical analysis, but this dropped to 42% by 2019. Among all the nine disciplines surveyed in 2019, only pharmacology significantly improved the data analysis indicators based on different genders, from 19% in 2009 to 48% in 2019. The above results indicate that although the proportion of animal experiments involving both sexes has increased, the academic community has not yet considered sex as an important variable that may affect the results of experiments. display. Canada and the United States have issued some policies requiring attention to gender variables in animal research for scientific research funding, and some important biological research hotspots, such as the European Union, Japan and China. The relevant policy has not been released yet. There is still insufficient attention to this issue.

  From the perspective of animal experiment ethics, pay attention to the influence of gender differences on experimental results should belong to the category of 3R principle experimental conditions optimization. Animal testing is conducted for human health. Due to gender differences in morbidity, performance and the occurrence of many diseases, only male animals are used for animal testing. Perhaps this sentence says "men were tested on animals. "Healthy" is more appropriate.