When is enough, enough?

Guest Post by Robyn Kirby

A year ago, Humane Research Australia learned that researchers at the University of Newcastle,NSW, had been subjecting mice to experiments that forced them to inhale cigarette smoke whilst crammed tightly into individual plastic tubes for 12 weeks at a time to study the effects of cigarette smoking on Chronic Obstructive Pulmonary Disease

www.humaneresearch.org.au/case-studies/mice-held-in-tubes-and-forced-to-inhale-cigarette-smoke-australia-s-outdated-research

Now, a year on, further inhumane studies have come to light as we learn that mice are still being restrained in inhalation chambers and forced to inhale cigarette smoke, but now to study the effects of cigarette smoking on female fertility and to study the human condition of Crohn’s Disease (an inflammatory disease of the gastrointestinal tract).

Let’s look further at these two latest studies.

Cigarette smoking and female fertility

Researchers at the University of Newcastle in Callaghan, NSW, have been nasally exposing mice to cigarette smoke for up to 12 weeks during pregnancy and lactation. Their female pups were then bred to create a grand-maternal exposed generation and again their female pups were bred to create a great-grand-maternal exposed generation. https://www.ncbi.nlm.nih.gov/pubmed/28402417

According to their publication, the researchers concluded “…that grandmaternal cigarette smoke exposure reduces female fertility in mice, highlighting the clinical need to promote the cessation of cigarette smoking in pregnant women”.  

Really?!  After all this time, expenditure of huge amounts of money, and vital resources and the expense of animals’ lives, the researchers can simply state we need to promote the cessation of cigarette smoking in pregnant women?  Is it not already a known fact that cigarette smoking decreases female fertility?

The publication states that funding for the experiment came from the National Health and Medical Research Council, amongst others.  Taxpayers’ funds surely would be better spent in informing women of the dangers of cigarette smoking on fertility rates with no woman left in doubt about the risks to fertility, rather than trying to recreate the fertility risks in female mice.  If there is any further doubt of the effects of cigarette smoking on fertility rates, epidemiological studies of humans are the preferable method of study.

Cigarette smoking and Crohn’s Disease

Cigarette smoke exposure and chronic obstructive pulmonary disease (COPD) are known to be risk factors of Crohn’s Disease (an inflammatory disease of the gastrointestinal tract).

Researchers (again) at the University of Newcastle (in conjunction with other institutes) used a mouse model of cigarette smoke exposure and an experimental model of COPD noting that chronic cigarette smoke (CS) exposure results in mild subclinical pathology in the colon. Colons in the mice showed to be shorter in CS exposed mice (as opposed to air exposed mice) and that cigarette smoke results in inflammatory changes in the colon. https://www.ncbi.nlm.nih.gov/pubmed/29415878

Acknowledging that etiology (cause of) Crohn’s Disease (CD) is “incompletely understood”, and that genetic, environmental and disease risk factors play an important role in CD, the researchers used mice to study this human condition.

If genetic, environmental and disease are risk factors in CD in humans, surely adding a different species into the mix could only complicate the etiology of CD.

Female mice were exposed to the smoke of 12 cigarettes twice a day 5 times a week for 12 weeks whilst held in an inhalation chamber. Further cohorts of mice were exposed to normal air.  And in smoking cessation experiments as part of the study, some mice were exposed for 8 weeks and exposed to normal air for further 4 weeks.

As if the smoking induced mice had not already suffered enough in the inhalation chambers, the researchers induced colitis (inflammation of the lining of colon) by chemically damaging the intestines of a set of mice (using the chemical TNBS). TNBS causes painful Crohn’s-like symptoms including bloody diarrhea and dramatic weight loss.  Induction by chemical damage is the cheapest way to induce colitis symptoms in mice and is often the chosen method simply because of its lower cost, however the condition of colitis causes great pain and distress in mice.  Disturbingly it appears that no analgesics were employed in these studies to relieve any of the animals in this study of their suffering.

The resultant inflammation was studied by way of a bronchoalveolar lavage (in which a bronchoscope is passed through mouth or nose and fluid is squirted into lungs and then collected for examination).  A cannula was inserted into the trachea and the lungs of mice inflated with 1 ml of tracer gas mixture and gas withdrawn.   After the mice were killed, their colons were removed and histological examinations made.

These extremely harsh experiments were carried out despite the patients with the disease already exist and yet only a very small number of Crohn’s Disease patients were recruited from the Royal Brisbane and Womens Hospitals with little reference in the publication to the results of these human studies.

Right: Custom-designed and purpose-built directed flow inhalation and smoke-exposure system., A mouse in one of the smoking chambers. Photo for educational purposes.

Photo credit: Copyright © 2017 Elsevier Inc. Journal of Allergy and Clinical Immunology 2013 131, 752-762.e7DOI: (10.1016/j.jaci.2012.11.053)http://www.jacionline.org/cms/attachment/2022388171/2042212475/fx1_lrg.jpg

What’s wrong with all of this?

• We already know that tobacco smoke contains more than 4500 chemicals, many of which are toxic.
• We already know that cigarette smoking decreases female fertility (in humans)
• We already know that we need to promote the cessation of cigarette smoking in pregnant women
• We already know that cigarette smoke is a risk factor for Crohn’s disease.
• We know that factors such as ethnic background, genetic, environmental impact on the effect of CD in humans (with mice only adding to this complication due to being a completely different species)
• Animal smoke models have limitations with every research group/institute using its own protocol for exposure and duration and varying amounts of toxic compounds used.
• The mice undoubtedly suffered stress from the smoke inhalation chambers and suffered pain and distress from chemically induced colitis.
• An artificially recreated disease in a once healthy animal does not make for a reliable model for the humane condition -  It is simply bad science.

These experiments have all been funded by the National Health and Medical Research Council using taxpayers’ funds. They continue to be approved by an animal ethics committee, which is “supposedly” there to ensure that unacceptable and unethical procedures are not carried out on animals.  

These experiments can only be described as unacceptable and unethical.  Yet since 2008 these and other dubious experiments have been approved by the University of Newcastle Animal Ethics Committee.  Why?

Enough is enough!

For further information about animal experiments: Please visit www.HumaneResearch.org.au
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