can I use female rats instead of male ones? - (Dec/16/2011 )

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.

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

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.....

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.

mtrnbh on Mon Dec 19 11:34:29 2011 said:

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

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.

Thank you ReResearcher for your kind reply.

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

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