14 replies to this topic

[mtrnbh]

Hi all,
I want to investigate the effect of a herbal extract on rats. I have ssen in papers that male wistar rats have been used for similar experiments. I have lots of female rats. can I use them or should I use male rats. Besides, why in most of the articles male rats have been used and whats the difference?
Thanks in advance.

[bob1]

Depends on the herbal extract... could it mimic a hormone?

[Biouday]

Only reason researcher avoid Female rats is because of its hormones ( oestrogen/ progesterone ) fluctuation during the menstruation cycle. This hormones fluctuation may influence your experiment there by your result. In male rats you donot have this problem thats what male rats are preferred over female rats.

Poor male rats.....

[mtrnbh]

thank you bob1 and biouday for your reply,

I don't know much about my herbal extract but apparently it is effective as a blood glucose lowering substance. I have done toxicity tests on female rats and the results have been fine. My experiments are not very extended most part will be done in a day in each rat. the only long term result will be the histopathological evaluation of liver and kidney. I would like to know if the results will be valid for publication if i use female rats. Thank you.

Edited by mtrnbh, 19 December 2011 - 03:35 AM.

[Biouday]

mtrnbh, on 19 December 2011 - 03:34 AM, said:

thank you bob1 and biouday for your reply,

I don't know much about my herbal extract but apparently it is effective as a blood glucose lowering substance. I have done toxicity tests on female rats and the results have been fine. My experiments are not very extended most part will be done in a day in each rat. the only long term result will be the histopathological evaluation of liver and kidney. I would like to know if the results will be valid for publication if i use female rats. Thank you.

You can check previous journals in pubmed, did any one performed similar kind of experiment in female rats.Then you can decided whether to do or not.

[Fungus_Dreams]

If similar research doesn't state a specific physiological reason against using females, it should be fine.

[ReResearcher]

We study diabetes and obesity and only use male rodents. Female rodents (because of estrogen) are  extremely resistant to developing metabolic disease. So, if you eventually plan to use a high-fat diet to induce insulin resistance and diabetes then see if your compound can correct the diabetes/lower blood sugar, I would not recommend females. If you will be using Streptozotocin to kill of some beta cells to cause hyperglycemia then give the compound, it should be fine.

Regardless, pick one and stick with it. Switching back and forth will make interpretation (and publication) very difficult.

Edited by ReResearcger, 08 January 2012 - 05:04 PM.

[mtrnbh]

Thank you ReResearcher for your kind reply.

[96well]

Males and females have a real different catabolism, therefore they may differentially dispose your herbal extract. Unfortunately, the female sex is largely neglected in biomedical research. If you are afraid to have more variation with females, just take females in the same estrous phase, you can simply make a vaginal smear and the metestrous is very easy to recognize. The best would be to make your principal test in both sexes and to look for gender-differences. You double the chances to find something interesting, and you may find a sex-difference that has a physiological impact.

Here is a good review: Rando and Wahli 2011,

Sex differences in nuclear receptor-regulated liver metabolic pathways.

Biochim Biophys Acta.

2011 Aug;1812(8):964-73

Pubmed link

[R.Mufti]

Hi everyone,

I need to know if I using female rats instead of male rats, will it affect my results because of the hormones? Can I have an example?
In my experiments I am measuring smooth muscle contractions and cytosolic calcium changes,

Thanks

[HOYAJM]

Unless there is a reason to only include female rats (i.e. uterus contraction studies) you should use a random population (male and female). Once you get your results, you can then compare male vs female to determine if there was indeed a difference. If there is you can then postulate that the female hormones were responsible for the observed differences.

[hobglobin]

You should try to search bioforum a bit more. Then you'd have found this thread

[Trof]

There is one thing I don't get, usually these rodent experiments are some kind of premilinary studies for future usage in humans, right?  You say female rat have cycle and hormones and everything and that it could spoil the neetiness of experiment.
Guess what? Human females also have cycle and hormones and stuff. So it's nice you'll have compact results, but what about the real meaning of the experiment as whole? What use are studies that exclude some part of normal population, because "it's troublesome"? You either want to see an effect of some substance on the model organism say-a-bit-close-to-human, however complex it may be or you want nice graphs.

[R.Mufti]

Thanks for you answer.
But I need to clarify more.
So my lab likes to use female rats (just because they are cheaper than the male rats).
However, other PIs are concerned about my results as the hormones could alter my results.
And I am close to finish, what should I do or say in this case?

[R.Mufti]

Thanks hobglobin