#glut4

[hallie-studies]

I've been spending some time in the lab and tonight I'll be developing my Western Blots, heres hoping they worked 🤞

[foodyscienceytrainingthings]

Awesome Post work out meal. 200g Grass fed mince beef, 100gbasmati rice, 100g mixed veg and 385g baked potatoes. Everything a growing boy (or girl) needs 😋. #postworkout #carbs #proteins #grassfed #glut4 #insulin #glycogenreplenishment

[mdsts]

アルドステロンは集合管においてナトリウムの再吸収とカリウムの排泄の役割を有している。ナトリウムの増加によって高血圧となり、カリウムの排泄が耐糖能異常を引き起こす。インスリンが筋細胞や肝臓の細胞に働く時にに、カリウムイオンの取り込みが必要なので、低カリウム血症であるとインスリンが正しく働けなくなってしまう。 インスリンは標的細胞膜上の受容体に結合し、それによって受容体はリン酸化され活性化し、細胞質内のIRS-1というタンパク質を更にリン酸化する。その後、何段階かのシグナル伝達を経て最終的にGLUT４というグルコース取り込みタンパクを細胞膜上に発現させる。すると、インスリンが作用した細胞はグルコースを取り込むことができるようになるのである。なお、GLUT4はカリウムの共輸送体なので血中のカリウムが低下しているとグルコースは細胞内に入れない。 また血症カリウム値は基準値内であっても低ければ低いほど糖尿病発症のリスクが増大するという報告もある。

[davern-travels]

***Occasionally, we'll drop in here with some Sciencey/Nursey stuff***

November 14th and GLUT4

The healthy human body is really good at regulating blood glucose (sugar) levels within a normal range. Why? I dunno. You might want to ask a philosopher that question. But, this regulation is significant for many reasons. First, human nerve cells (like the cells that make up your brain) rely on glucose exclusively for energy. A lack of blood glucose and your brain cells will starve and die. Second, but not lastly, muscle cells also rely on glucose for energy, although they do have the ability to use other fuels. During physical activity (i.e., exercise), muscle becomes more and more reliant on glucose/glycogen for energy production, however. Short story: glucose is kinda a big deal and, therefore, blood sugar levels are kinda important too.

But, how does blood glucose get into the cells as needed? There are a lot of players and steps involved here. I want to focus, though, on the glucose transporter isoforms. They go by short hand GLUT1 and GLUT4, for example. Certain cells, like brain cells contain GLUT1 (short for glucose transporter #1). GLUT1 is pretty awesome because it can work nearly independently at the cell membrane and shuttle in all the glucose it wants from the blood to the inside of the cell. Skeletal muscle cells, however, don't so much have the awesomeness of GLUT1. Skeletal muscle cells mostly rely on its cousin GLUT4 (you guessed it, glucose transporter #4).

  Briefly, GLUT4 can also shuttle glucose across the cell membrane. But, GLUT4 lives within muscle cells and relies on some kind of a specific signal in order to get it to do its job. Most people are very familiar with the first signal: Insulin.  The body uses insulin as a signal to transport glucose from the blood and into many different types of cells. We'll stick to (skeletal) muscle here. Insulin is a hormone that binds with its receptor on the muscle cell membrane. This union of insulin to receptor triggers a second messenger system that springs GLUT4 into action. Thus, blood sugar decreases and muscle glycogen increases. Here is where we insert most of our common notions of eating "carbs" and stimulating large rises of blood glucose and insulin! This process is largely thought of as a bad thing. But, biologically speaking, it is physiology that is necessary for survival.  It is also oversimplification. 

Besides insulin, GLUT4 has another major "signal". There is another natural process that starts the same cascade of events as the binding of insulin to its receptor. What is it? Muscle contraction.  That's right. Muscle contraction (as happens during exercise) also signals GLUT4 to do its job and transport glucose from the blood into muscle cells. This transport is insulin independent. What's even cooler is that some awesome research over the last 50 years suggests that regular physical exercise increases the gene expression of GLUT4 and that even insulin sensitivity may be increased for several hours after the end of a single bout of exercise.

So, insulin gets all the attention. But in order to understand how the body regulates blood sugar, you have to understand the full picture of how GLUT4 operates, also. The specifics of GLUT4 physiology are an important reason why regular physical activity is so important to both the prevention and treatment of Type 2 Diabetes. So get out there! Walk your 4-legged friend! Hit the gym. Do whatever, but just move and contract those beautiful muscles of yours! By the way, happy November 14th, which is World Diabetes Day.

[vascularbiology]

Department of Physiology and Biophysics Symposium (Part 2 of 3)

Series: Department of Physiology and Biophysics Symposium Title: Lifton - New Insights into Integrated Physiology from Human Genetics and Genomics Klip - Divergent and Vonvergent Insulin Signals Mobilizing the GLUT4 Glucose Transporter in Muscle Cells Speakers: Richard Lifton, M.D., Ph.D. - Chairman of Dept. of Genetics and Internal Medicine, Genomics, and Investigator, Yale University Amira Klip, Ph.D. - Professor of Physiology, Biochemistry, and Pediatrics, Senior Scientist, University of Toronto Date: 29 April 2009 Location: Robbins Building E501, Case School of Medicine in Cleveland, OH