The Fat Cell 9: Enter Insulin
A Fast Fix for a Feast?
After a meal is eaten, glucose rides around the bloodstream. Upon reaching the pancreas, the spongy fish-shaped organ, nestled behind the stomach, kicks out a hormone, insulin. Now both glucose and insulin are cruising around. The insulin alerts the muscles that it has arrived - like the doorbell signaling that lunch is on the doorstep. The muscle cell captures the glucose with a GLUT 4 molecule and uses the glucose for immediate projects.
The insulin also alerts the fat cell in a similar manner. As the insulin encounters the adipocyte (the fat cell), it snuggles into a receptor on the fat cell's surface that is exactly fit to its specification. The positioning kicks off the doorbell cascade and molecules within the fat cell, GLUT 4 molecules, rise to the surface in a submarine-like carrier, a vesicle. The vesicle fuses with the surface membrane and exposes the GLUT 4 molecule to the outside of the cell where it encounters the glucose riding the bloodstream, captures it and brings it inside the cell to be stored.
Mechanism of the Action of Insulin by Luuis12321, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
Studies have shown that in between meals the GLUT 4 molecules on the surfaces are present but sparse and hang out in clusters. When glucose suffuses the bloodstream, GLUT 4, rapidly dots the surface with four times the number of molecules within three minutes. Within 10 to 15 minutes, the GLUT molecules have subsided. 
At least that’s the way it is supposed to work. How it works under the influence of inflammatory conditions produced by obesity is a story for the next article.
My personal journey to avoid Type 2 diabetes is progressing satisfactorily. I weighed in at 185.2 lbs, down 11.8 lbs since the beginning nine weeks ago; but I consider myself lucky this week. I stuffed myself with Indian food to which my mother treated my family for my birthday (the leptin failed utterly) so I fasted the next day in penance and in panic.
I have fasted before. The longest was for seven days (just for the record I am not recommending anything - technically I should have checked with a doctor - I'm just writing about what I did). I am not sure how I feel about it for weight loss because I usually just gain the weight right back; perhaps whole-foods-plant-based will make a difference. The effort was never a loss though. The purpose was usually not to shed weight. It was an attempt at recentering which is necessary when the whirling in my head gets out of control. It helps. I should probably take up meditation. In the meantime, an occasional fast is lovely.
Physically, more and more studies are demonstrating that the body and the brain responds positively to fasting.
In relation to insulin, a significant decrease in calories quickly decreases inflammation within the hypothalamus in the brain which decreases the insulin resistance even before any weight has been loss . The benefits are so overwhelming it is as if we were designed to fast and we probably were. The hypothesis is that as a species, perhaps all vertebrates, perhaps even all animal cell based life forms, regularly went through periods of starvation as it evolved; therefore, the animals that could withstand or even prosper during famine conditions were more likely to survived. The result may have been an organism that fares better with occasional fasting.
Perhaps fasting nudged the scale downward for me this week but the real test will be next week's numbers. This is a journey in changing habits. I am learning as I go - like Kathryn who has, hurray! hurrah! found her way back to the keyboard. Thank goodness. I need her.
 NIH study shows how insulin stimulates fat cells to take in glucosehttps://www.nih.gov/news-events/news-releases/nih-study-shows-how-insulin-stimulates-fat-cells-take-glucose#:~:text=In%20response%2C%20the%20pancreas%20secretes,come%20to%20the%20cell's%20surface.
 Sears B, Perry M. The role of fatty acids in insulin resistance. Lipids Health Dis. 2015 Sep 29;14:121. doi: 10.1186/s12944-015-0123-1. PMID: 26415887; PMCID: PMC4587882.
About the Creator
D. Thea Baldrick
By wedding two strange bedfellows, bachelor degrees in Biology and Literature, the resulting chimeric offspring are stories laced with science. I publish with thecollector.com and Underland Arcana. Unearth at dthea.com
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