LIRKO mice (3) The MCQ

**************EDIT - This is serious**************

It has been pointed out that this post is a deliberate intention to mislead. I would like to deny this categorically. The allegation is based around my personal error relating to the renal glycosuria threshold of rats. I have never treated a rat for diabetes. Apparently they do not become glycosuric until blood glucose exceeds around 400mg/dl, somewhat above the glycaemic level of LIRKO mice and waaaay above the cat, dog or human threshold.

They are still functionally diabetic, despite the lack of glycosuria, in terms of hyperglycaemia. But it appears that YOU CANNOT MAKE JAM from their urine.

I would really like to say I hope Dr Guyenet did not waste too much time trying to get his rather watery jam to set. But I just can't. I guess he spent a lot of hours.

Mea culpa.

Sorry to anyone other than Dr G who tried this. Better buy your jam ready made.

******************END EDIT******************
I see the LIRKO mouse has resurfaced as a destructor of the role of insulin in obesity yet again. I've posted on the LIRKO mouse in the past so this little quizz should be quite straight forward. I skipped the questions about leptin because I felt like it.

WARNING some of the questions may have more than one correct answer.

Q1. What is the blood glucose of a LIRKO mouse after a mouthfull of chow?
a. 400mg/dl
b. 400mg/dl
c. 400mg/dl
d. WTF, no one told me LIRKO mice are intensely diabetic.

Q2. What is the urine glucose concentration of a LIRKO mouse?
a. Some
b. Quite a lot
c. More than quite a lot
d. Obesity researchers boil it down to make jam.

Q3. The liver of a LIRKO mouse has no access to glucose. Where does it source it's energy?
a. Not from glucose
b. Definitely not from glucose
c. Absolutely, definitely not from glucose
d. Where's the fat?

Q4. How much fat is there in mouse diet F9?
a. Not a lot.
b. Not a lot
e. Not a lot
d. 10%, just about enough to run the liver on, rather badly, giving early onset cirrhosis and death.

Q5. How much de novo lipogenesis (DNL) from glucose is done in the liver of a LIRKO mouse?
a. None
b. Zero
c. Zilch
d. LIRKO mouse liver can't take up glucose for anything because it has no insulin receptors. Ha ha, gotcha, this is a trick question.

Q6. If the dietary fat is used to run the liver and there is no DNL, where does the fat in adipose tissue fat come from?
a. Thin air.
b. Spontaneous generation
c. Beamed in from The Enterprise
d. A small nuclear reactor
e. It doesn't, you can't put in what you haven't got. OK, there is a smidge of DNL in adipocytes.

Q7. If a LIRKO mouse at the gym is losing more calories down the urinals (where glucose is collected for making jam) than it burns on the treadmill, why doesn't it eat more?
a. Blood glucose is 400mg/dl
b. Blood insulin is 80ng/ml
c. Both.
d. Yeugh, is that really how they make jam?

Q8. The LIRKO mouse is hyperinsulinaemic. By how much does this lower plasma free fatty acids?
a. By 40%
b. By 40%
c. By 40%
d. By only 40% because adipocytes, like the rest of the mouse, are intensely insulin resistant.
e. WTF, no one told me they had depressed FFAs.

Q9. How would the LIRKO mouse cope with a saturated fat based, intensely ketogenic diet?
a. Well
b. Really well
c. Really, really well
d. Don't ask, don't even think about it.

Q10. Obesity researchers trot out the LIRKO mouse because:
a. They want to share
b. They want to share
c. They want to share
d. Shut up and eat your carbohydrate. You need insulin to get slim. Mmmm LIRKO jam...

Peter