If not insulin, that what is the magic word?
April 10, 2012 2:11 PM Subscribe
Why can't brain cells collect glucose in a concentration from the blood or how do the cells break it down?
I understand that the body needs insulin to facilitate the movement of glucose into the cells, also that the brain cells do not rely on insulin to utilize glucose in the blood.
Yet, my book states, "The brain cells cannot make glucose, they cannot
store glucose for more than a few minutes, nor can they collect glucose in a concentration from the blood."
A paragraph further down reads, "One organ that does not need insulin to help move glucose into the cells is the brain. Glucose will cross the blood-brain barrier readily, whether insulin is present or not."
So what does the brain cell use to transfer concentrated glucose from the blood?
I'm in school for Emergency Medical Tech, this is not a homework question, I'm just confused at the contradiction.
I understand that the body needs insulin to facilitate the movement of glucose into the cells, also that the brain cells do not rely on insulin to utilize glucose in the blood.
Yet, my book states, "The brain cells cannot make glucose, they cannot
store glucose for more than a few minutes, nor can they collect glucose in a concentration from the blood."
A paragraph further down reads, "One organ that does not need insulin to help move glucose into the cells is the brain. Glucose will cross the blood-brain barrier readily, whether insulin is present or not."
So what does the brain cell use to transfer concentrated glucose from the blood?
I'm in school for Emergency Medical Tech, this is not a homework question, I'm just confused at the contradiction.
Best answer: This paper is a little technical, but generally demonstrates the relationship.
I'm not sure what that bolded section means, but my guess would be that they meant they cannon collect glucose in a concentration above the blood concentration. That's just my under-educated guess though.
posted by jhs at 2:49 PM on April 10, 2012
I'm not sure what that bolded section means, but my guess would be that they meant they cannon collect glucose in a concentration above the blood concentration. That's just my under-educated guess though.
posted by jhs at 2:49 PM on April 10, 2012
Best answer: In order to understand what brain cells use to move glucose intracellularly, you should learn a little more about glucose transporter protein complexes. Specific GLUTs that aren't insulin-dependent (in contrast to GLUT4 present in, for example, adipose tissue and striated muscle, which DO depend on the presence of insulin in order to be functional) are present in neuronal cell membranes.
posted by killdevil at 3:07 PM on April 10, 2012
posted by killdevil at 3:07 PM on April 10, 2012
Response by poster: GLUT 1 seems like the most likely candidate, as long as there is a level of glucose is compatible with life.
The links were fascinating, yes, I read them all. Each one explained part of the puzzle.
posted by JujuB at 4:13 PM on April 10, 2012 [1 favorite]
The links were fascinating, yes, I read them all. Each one explained part of the puzzle.
posted by JujuB at 4:13 PM on April 10, 2012 [1 favorite]
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Link 1
Link 2
posted by empyrean at 2:31 PM on April 10, 2012