Male bias in research with animal models prevents women from getting best drugs

[xSilverPhinx]

Women are missing out on optimum medical treatment because most pre-clinical drug research is done in male animals, a new study suggests.

Research on male animals prevents women from getting best drugs  (NewScientist).

Full Open Access paper here (Nature Communications).

Personally I think it's absurd that only up to recently the female phenotype was so neglected in both pre-clinical (using animal models) and clinical (on humans) trials.

[Dave]

Personally I think it's absurd that only up to recently the female phenotype was so neglected in both pre-clinical (using animal models) and clinical (on humans) trials.

Absurd? Imbecilic!

[No one]

Seems like a move only a big dick would make.

[Arturo]

Animals =/= humans. Pretty sure they do human trials with men and women

[Claireliontamer]

I wonder why they just use the males?  It surely can't be that much more difficult to include female animals too.

[Dave]

I wonder why they just use the males?  It surely can't be that much more difficult to include female animals too.

If it was chickens, goats, sheep, cattle and other food animals they were experimenting on I could understand it.

The males are mostly surplus, expendable, only fit for eating or other purposes...

[Recusant]

Good thread, xSilverPhinx. Though this problem has been recognized previously, solid data is always useful.

[xSilverPhinx]

Animals =/= humans. Pretty sure they do human trials with men and women

While there has been the growing tendency to add more women in clinical trials in recent years it's what comes before that's the problem. The whole point of pre-clinical trials with animal models is to test drugs before they're marketed. If most pre-clinical studies use males then that can be to the detriment of females in later stages.

For instance, in one of my projects we investigated the effect of fluoxetine (prozac) on the extinction of aversive memories. With males we got one result, with females it was the complete opposite! We redid the experiment with both males and females but replicated our previous results.  Prozac is also used to treat PTSD, which is way more prevalent in women than in men, so sex differences are relevant. 

In another experiment investigating memory generalisation with adolescents we use both males and females, and they are different. Generalisation of aversive memories is a symptom of some anxiety disorders such as PTSD and Generalised Anxiety Disorder.

In yet another experiment on the effects of caffeine on aversive memories we tried to use females as well as males, but females are so frustrating to work with that we gave up.

[xSilverPhinx]

I wonder why they just use the males?  It surely can't be that much more difficult to include female animals too.

Females are...complicated. Their estrus cycle (proestrus, estus, metaestrus and diestrus) means that hormones can vary within the same day, estrus typically lasts only about 4 hours in rats, depending on whether there are males near enough for the female to pick up on pheromones. 

Males are less variable and experiments using them are 'cleaner' as well, with smaller standard deviations and variance. Error bars in experiments using females tends to be much larger, which means that histograms aren't as pretty.

There are ethical reasons not to use females as well. If you need a population of about 9 to 10 animals per group in an experiment, ideally you ought to pool together that number of females in each stage of the estrus cycle, which means you end up using a lot more animals. That's one major reason why many opt to use just males. 

[xSilverPhinx]

The males are mostly surplus, expendable, only fit for eating or other purposes...

No, of course not. 

[xSilverPhinx]

Good thread, xSilverPhinx. Though this problem has been recognized previously, solid data is always useful.

I was aware previously that some funding programs were calling for more experiments and pre-clinical trials to be done with females, but what really surprised me is just how slow progress in that sense has been.   

[Arturo]

Animals =/= humans. Pretty sure they do human trials with men and women

but females are so frustrating to work with that we gave up.

bahahaha I had to read this twice because I though this part was about anxiety disorders with women

I wonder how much psychology do they teach you down there? It might come to be useful or get someone who can handle them. That's scenario is probably more prevalent in the usa though because everyone comes here to do science.

[xSilverPhinx]

Animals =/= humans. Pretty sure they do human trials with men and women

but females are so frustrating to work with that we gave up.

bahahaha I had to read this twice because I though this part was about anxiety disorders with women

No, female rats tend to be more anxious but we spend about 3 or 4 days handling them so that they get used to being manipulated (we do the same with the males). That way their anxiety levels lessen. We gave up because nothing we did resulted in positive results. 

I wonder how much psychology do they teach you down there? It might come to be useful or get someone who can handle them. That's scenario is probably more prevalent in the usa though because everyone comes here to do science.

I didn't take any psychology classes, my training is in biology (mostly biophysics and neurophysiology). Our system is different here, we don't major in one field and minor in another.

Neuroscience is a multidisciplinary field, but it's my impression that a lot of the more famous American neuroscientists in researching memory such as James McGaugh are psychologists. 

[Arturo]

I could see how it would be useful

[xSilverPhinx]

I could see how it would be useful

It is, especially if you want to work with people as subjects.