Mice don’t menstruate!?

Attended a radioactive substances lab audit today where the professor expressed an interest in renewing the license for using animals as part of the research and mentioned that the application for the license would involve at least 3 weeks of full time work.

ASPA 1986

It turns out that there is not a special radioactive animals license but instead a license from the Home Office to adhere to the Animals (Scientific Procedures) Act 1986 (ASPA) for the use of animals within research.  I then went slightly down the rabbit hole to see what this involves after someone told me that the animals aren’t allowed to look at each other…. (spoiler alert, not entirely true).

Protected animals are “All living vertebrates, other than a human, including certain immature forms, and any living cephalopod”. Invertebrates such as fruit flies and nematodes are not protected under most animal research legislation, and therefore the total number of invertebrates used in research remains unknown.

The UK government’s guidance on the operation of ASPA includes these requirements:

  • Incompatible species (for example predator-prey species) may not be housed in the same room. In the case of predator and prey, they should not be housed within sight, smell or sound of each other.
  • Rats are opportunistic predators of mice, so it is advised that you don’t house them in the same room as it could be stressful to either/both species and thus separating them reduces the potential for scientific variability.
  • Controlled lighting should be used to satisfy the biological requirements of the animals if natural light does not provide an appropriate light/dark cycle.
  • Dogs shall not be single housed for more than four hours at a time.
  • Rabbits are easily frightened by sudden unexpected loud noise and may injure themselves in panic. Some forms of low level background noise in the animal room may be beneficial in reducing the impact of sudden loud noises.

After learning all of this (and so much more than I ever needed or wanted to know), I wondered what sort of research projects involve animals and stumbled across a wonderful non-technical summary of projects granted approval in 2016. My intense fascination with reproductive systems lead me to read the summary of approved projects on urogenital disorders.

Mice with endometriosis

This enabled the revelation that apparently mice don’t menstruate usually or develop endometriosis but can be stimulated to undergo a process very similar to human menstruation using hormones following ovary removal. Material can then be collected and introduced into the pelvic cavity of recipient mice to induce endometriosis. 

Mice are the smallest mammalian species in which the function of the endometrium can be studied. The lack of womb precludes the use of lower experimental organisms such as flies, frogs or fish. Endometriosis only develops in humans and some high primates. So mice are the best option for inducing endometriosis in research despite their lack of natural periods.

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/662364/Guidance_on_the_Operation_of_ASPA.pdf

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/670151/Vol_24_TAR_Human_Urogenital_Disorders.pdf

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