Although this was an excellent explanation I have to be a bit semantic on one small thing. Glucose itself isn't "toxic" - not literally, physiologically speaking at least. The reason why high glucose levels have adverse effects has to do with the principles of tonicity; i.e. when a high concentration of a solute exists in a certain location it will pull water towards it. (Incidentally this is why medics don't use 50% Dextrose solutions with diabetic patients anymore - because the concentration of the sugar was so high that after a few minutes of use it would begin to necrose the tissue around the IV site). At any rate it was an excellent explanation but I couldn't help myself in correcting that small piece at the end. Cheers!
Extremely helpful! Been diabetic for 13+ years. Before severe injury in 2006 was able to keep A1C's around 5.7-5.9 WITHOUT Meds by riding and hiking. Now I can't exercise and I take pills and my A1c's are 6.3-6.9. Control what I eat carefully but can't loose weight, esp with menopause now. I hate this but can't seem to do much. The less I eat the more my body stores fat. Peace, Avie
Really insightful and i know this video was posted years ago but I am interested in the physical activity aspect. You stated that if you are physically active then no insulin is needed for GLUT4 to transport glucose into the cells, how is that possible? I thought physical activity only increased insulin sensitivity, allowing less for the facilitated diffusion to occur, not that it doesn't need insulin at all. If anyone can help me understand, I would really appreciate it :)
GLUT 4 is always dependent on insulin to uptake glucose from what i know from text books. GLUT 1 is insulin independent. If you can give me the source of the information that exercise can induce glucose uptake into the cell without insulin, please post me a link. I really much would appreciate it.
@Bennyhidef Any sort of muscle contraction will work to cause translocation of GLUT-4. Strength training will recruit more muscle fibers for a limited period of time whereas aerobic exercise will recruit fewer muscle fibers for an extended period of time. Both have their benefits. I'd prescribe aerobic exercise because it is easier and has more health benefits than strength training, but people like to look good too.
lowers the blood sugar by triggering cells to accept glucose (blood sugar) into them for energy. sorry if this sounds basics but I am trying to understand this insulin, blood sugar, fat thing. If I knew was going to be fat in Bio class maybe this wouldn't be necessary. But Im learning thanks to Drs like you.
Glucose can enter the cell via GLUT1 under basal condition. Insulin increases the uptake by increasing GLUT4 expression. This is the reason why T1 diabetics don't need to inject as much insulin if they exercise.
No, because if the glucose-levels in the cells are too high they will turn them into fatty acids and store them as fat in adipose tissue. That's how you get fat from Cola even though it contains zero fat.
Great lesson! I had a question about GLUT4, can glucose leave the cell via GLUT4? In the absence of insulin, would the increased rate of glycogenolysis result in a greater cellular glucose output? Many thanks
got my exam tomorrow, i must've looked through so many videos on diabetes. none of which mentioned anything about GLUT 4!! i assumed glucose made its way through the insulin receptors once it had insulin connected to it like a funnell!! great video your a lifesaver!!!!!
Thanks for posting, and taking us past the basics of insulin. ...after watching this a few times, I'm wondering how the "exercise induced" glut-4 receptors work...how does exercise work to engage them?
Man you good! This is real helpful for me to know! I take the knowledge that I learn from you and help others..azz well azz myself! Thanks..Keep doing your thing!!!
