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I've heard from animal rights activists that experiments on animals are not necessary because we can get the same or better results from cell culture experiments.

An example of that claim is this excerpt from a comment on a blog:

2) According to the former scientific executive of Huntingdon Life Sciences, animal tests and human results agree “5%-25% of the time.”

3) Among the hundreds of techniques available instead of animal experiments, cell culture toxicology methods give accuracy rates of 80-85%

Posted in the comments section on Respectful Insolence

I don't want to focus on the exact numbers given here, but on the general issue of toxicology testing using animals and cell cultures. Determining the safety of new chemical compounds, drugs etc. is a major use of animal experiments, I'll focus my question on these toxicological studies.

Can cell culture methods effectively replace animal experiments for toxicological studies?

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    I think "toxicology" should be added to the title. – Rusty Mar 31 '11 at 16:29
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    Since this is just my opinion as an environmental chemist, I'm not going to list it as an answer. Cell culture toxicology is definitely a worthwhile tool for determining some aspects of toxicology, but in my opinion it cannot replace animal experiments for the 'entire picture' so to speak. Some animal tests can be better applied to human physiology than others, this is true. But the whole point of toxicologists isn't just what's toxic to us as humans. It's also a matter of what's toxic in the environment to other animals - and the test animals we use are good 'representatives' – Darwy Mar 31 '11 at 16:54
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    for other species which are particularly vulnerable in the environment. Daphnia magna, Danio rerio, etc - these are all well studied animals in toxicology (just to name two), whose physiology is well known and understood. I'm currently testing nanomaterials (ZnO, Ag, and CNT's) and their toxiological effects on Daphnia - there is SO much we don't understand about how these new materials can effect organisms in the environment - and ultimately us. – Darwy Mar 31 '11 at 16:57
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    The issue still remains that pharmaceuticals end up in our waters; whether or not they're the original compound or a metabolite that we've excreted. Unfortunately the drug studies often don't take into consideration what percentage of the drug ends up in the environment. – Darwy Mar 31 '11 at 21:02
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    @Monkey Again, I'll refer to nanotechnology: ncbi.nlm.nih.gov/pmc/articles/PMC2695593 They're using nanomaterials in a clinical trial for chemotherapy - it has great promise for treating cancer; but it's a big ?? as to what's going to happen to the CNT's after they've eliminated the cancer cell. It's not just an environmental consideration (assuming the CNT's are excreted) - the CNT's are still in the body - what do they do to the liver? To the kidneys? Will they cause lymphatic issues? Arthritis? An in vitro experiment can't answer it all. – Darwy Mar 31 '11 at 22:27
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Ok, now with the edited question I'm going to weigh in.

No. Cell culture methods cannot effectively replace animal experiments for Toxicological studies.

While it will make some advances in toxicology, notably helping ensure products are safer when they come to market, it still doesn't give the 'full picture' of the life of a compound. They do wonders for xenbiotic compounds at the cellular and genetic level, but they cannot encompass all aspects of the toxicological picture.

Let's consider the in vitro tox screening for Ibuprofen.

In vitro studies have been done re: Bilirubin toxicity. (http://journals.lww.com/pedresearch/Fulltext/2009/04000/Ibuprofen_Augments_Bilirubin_Toxicity_in_Rat.6.aspx)

Other cytotoxic studies have been performed with rainbow trout and cellular cultures:

http://onlinelibrary.wiley.com/doi/10.1002/tox.20410/abstract

Does this compound bioaccumulate? Is it Biomagnified? These questions can't be answered via a cellular study.

Does this compound produce metabolites?? (yes!) - what is the process of degradation by the organism? How are the compounds excreted from the organism? Is this compound stored in fat? Are the metabolites stored in fat?

If you're curious about the metabolites of Ibuprofen in water, here's an example: http://www.ncbi.nlm.nih.gov/pubmed/15212901

A single cellular culture array cannot answer all the pertinent questions. It gives us an excellent picture of cellular disruptions, genetic impacts and such, but cannot compensate for the entire physiology of a test subject.

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Your citation only apply to toxicology but your general question doesn’t original question wasn’t. So I’ll pick the remaining part.

Animal experiments are unfortunately (still) necessary. Most of the fundamental research today is conducted on animals and for the foreseeable time this will remain so.

Cell cultures and mathematical models are entirely inadequate in most fundamental research since we don’t know what to model. Just consider embryology which studies the developmental processes that lead to an adult animal. Understanding these processes is fundamental for our general understanding of biology and consequently future medicine.

Unfortunately, a big part of this research consists of mapping the embryology by cutting apart mouse embryos to take tissue samples (e.g. Mouse atlas).

This is true of basically every biological and clinical research. I’ll give two examples to illustrate this.

  • Diabetes mellitus is today one of the most prevalent diseases, an epidemic, and one of the major causes of death in the developed world (source: CDC). A lot of research goes into understanding it – and most of this research uses animal models – more precisely, mouse models (examples: 1, 2, 3, …).

  • Muscle development is regulated by a host of proteins. One of them is myostatin. Research into this protein could lead to cures for muscular atrophy which is ultimately the cause of death for several diseases such as DMD – Duchenne muscular dystrophy.

The information gained through these experiments cannot be replicated otherwise. In fact, there’s a big incentive for the industry and governments to use cell cultures or models instead – because they are vastly cheaper than experimenting on live animals. Industry interests and animal rights interests perfectly align in this regard so we can be fairly confident that the industry and public research are indeed doing their best to replace animal experiments by other methods.

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    Hi Konrad - please reference your answer. Thanks! :-) – Sklivvz Mar 31 '11 at 20:01
  • I think the question isn't really about the value of animal experiments for fundamental research but about the value of animal experiments for pharma toxicology tests. Could you add something about the issue of testing for toxicology? – Christian Mar 31 '11 at 21:00
  • Why the double negative in "not unnecessary"? – dbkk Apr 1 '11 at 4:51
  • @dbkk Because I’m directly negating the question, which asked after “unnecesary”. – Konrad Rudolph Apr 1 '11 at 8:50
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    @Christian I really prefer not to. The issue of toxicology is really muddied (theskepticsguide.org/archive/podcastinfo.aspx?mid=1&pid=290). I don’t feel competent enough to comment. Furthermore, as I’ve explicitly noted in my answer, the original question did not exclusively ask about toxicology research. – Konrad Rudolph Apr 1 '11 at 9:00

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