Fasting Of MIce -- Impact On Results Of Studies

[Giraffe]

Is fasting for 16 hours in mice the same for humans or do you have to extrapolate?
I thought mice will only last 3 days without food?
I'm sure they had water? Not sure of the methods.

This review is quite interesting.

Fasting of mice: a review

 

[Drareg]

This review is quite interesting.

Fasting of mice: a review

Thanks,this is a must read,deserves a thread of its own,alarmingly something like this is only written in 2013.
This practice needs to become law,it's clear as day it's being corrupted.

On top of all the other issues with mice studies we now need to take into account if they were eating "sticks" ,their own "poo"and possibly other mice "poo"while fasting or just in general as the mice chow is so bad.
The sticks were probably treated with "linseed oil" or something flammable.

Now what would happen in human trials if people started eating their own poo and others poo on top of sticks for dessert while stuck in tiny rooms while being starved,IT WAS NIACINAMIDES FAULT!

Makes we wonder about the burrs "essential fatty acid deficiency" trial,the mice may have been eating poo and sticks hence the skin issues.
It wouldn't surprise me if somehow big pharma manipulate the results from the poo and stick diet for a new blockbuster drug.

 

[Giraffe]

I decided to move the posts to a new thread.

Many studies on mice are done in a fasted state, and this has impact on the result. Peat has mentioned that you can get upside-down results if you use rodents because most of them are nocturnal animals. He said in rodents cortisol can increase bone strength. "There are some situations like a prolactin in rats will increase progesterone, where in humans it generally decreases it." You have to take into account at what time of the day they got injections.

The review lists many more expamples (mainly related to the fasted state).

Mice lost significantly more weight after 16 h of fasting compared with 4 h, and a significantly (P < 0.05) larger weight loss was reported after 18 h of fasting compared with 5 h of fasting, 16% and 5%, respectively.21,66 Sokolović et al. found that after 12 h of fasting the weight loss was steady at a rate of approximately 7% per day, based on a total of 72 h of recordings.68

Non-fasted mice do not normally exhibit torpor.87–89 Mice can become torpid after about 7 h of fasting, with a body temperature drop of up to 15℃.60,89,90 The mean time from initiation of fasting to first torpor bout was reported to be 13.3 h in a study by Brown and Staples.89 It has been stated that torpor typically occurs after 8 h of fasting, and/or at the end of the dark cycle which is coincident with the peak of circulating ghrelin. Ghrelin is able to deepen torpor.91 A food restriction of 50% for three days also induced torpor.51

Handling of mice for subcutaneous injection or insertion of a rectal probe causes immediate arousal from the torpid state.88,90

This describes a typical study situation: semi-starved mice (16-hours fast) get aroused from torpor to receive an injection.

......

Makes we wonder about the burrs "essential fatty acid deficiency" trial,the mice may have been eating poo and sticks hence the skin issues.

Sometimes the animals are housed in hanging cages to prevent that they eat poo (studies about caloric restriction or micronutrient depletion).

The Burr's themselves wrote that the skin lesions reminded them of pellagra. Vitamin B6 was not known at that time, but it was later shown that it cures these lessions. Vitamin B6 is a required cofactor in the tryptophan-to-niacin reaction.

 

[Drareg]

I decided to move the posts to a new thread.

Many studies on mice are done in a fasted state, and this has impact on the result. Peat has mentioned that you can get upside-down results if you use rodents because most of them are nocturnal animals. He said in rodents cortisol can increase bone strength. "There are some situations like a prolactin in rats will increase progesterone, where in humans it generally decreases it." You have to take into account at what time of the day they got injections.

The review lists many more expamples (mainly related to the fasted state).






This describes a typical study situation: semi-starved mice (16-hours fast) get aroused from torpor to receive an injection.

......


Sometimes the animals are housed in hanging cages to prevent that they eat poo (studies about caloric restriction or micronutrient depletion).

The Burr's themselves wrote that the skin lesions reminded them of pellagra. Vitamin B6 was not known at that time, but it was later shown that it cures these lessions. Vitamin B6 is a required cofactor in the tryptophan-to-niacin reaction.

At least they know about the sticks and poo eating but it seems only for caloric restriction or micronutrients,this would still have effected outcomes in other areas.
The Cages should reflect the natural environment somewhat,they may be lab born animals but the epigentics are still at play imo.

The argument against B6 curing the mice in the Burrs study is it helped mobilise arachidonic acid from the fat stores,it's claimed the mice would inherit some level of arachidonic acid from the mother I believe.
We would need to breed out the PUFA over 3 generations to insure no sneaky stores of PUFA anywhere,check mice before starting study.
I find it's strange that such an essential fatty acid needed B6 to get mobilised particularly when it was needed most.

The ideal "essentiality",study should be done on dogs,would cost very little, what's even more salient after reading the study you posted on mice is that the animals tested are in an open environment of sort,if their metabolism is increasing from no PUFA and they are provided enough food,the environment would have to be stimulating,they would behave very strange in cramped and boring quarters,researchers would document this behaviour whatever way they like.