Insulin stimulates glucose uptake

Metformin restrains hepatic glucose production principally by suppression of gluconeogenesis. The mechanisms involve potentiation of insulin action and decreased hepatic extraction of certain gluconeogenic substrates such as lactate. In addition, metformin reduces the rate of hepatic glycogenolysis and decreases the activity of hepatic glucose-6-phosphatase. Insulin-stimulated glucose uptake and glycogenesis by skeletal muscle is increased by metformin mainly by increased... 

Carayannopoulos, M. O., et al. GLUT8 is a glucose transporter responsible for insulin-stimulated glucose uptake in the blastocyst. Proc. Natl. Acad. Sci. U. S. A. 2000, 97, 7313-7318. 

It was discovered nearly 20 years ago that V(V) as vanadate and V(IV) as vanadyl can mimic some of the effects of insulin (stimulate glucose uptake and oxidation and glycogen synthesis) (512, 513). Vanadate is an effective insulin mimetic in the diabetic rat (514), but has proved to be too toxic for human use. Vanadyl, as VOS04, is also unsuitable because high doses are needed on account of its poor oral absorption. Vanadium complexes with organic ligands have proved to be less toxic and can have improved aqueous solubility and lipophil-icity. 

GLUT 4 Skeletal muscle Adipose tissue 5 mM Insulin-stimulated glucose uptake... 

To gain further insight into the mechanisms involved in defective insulin-stimulated glucose uptake in skeletal muscle of insulin-resistant subjects, the possible role of IMCL in the pathogenesis of skeletal muscle insulin resistance and type 2 diabetes mellitus was explored by comparing insulin sensitivity (GIR) and IMCL content of insulin-resistant and insulin-sensitive offsprings of patients with type 2 diabetes. Twenty-six healthy subjects were included in the first study, 13 of them classified as insulin-sensitive and further 13 as insulin-resistant. Metabolic and anthropometric data are given in Table 4. 

Changes in the blood levels of these hormones all contribute to regulation of blood glncose level in several conditions. After a meal glucose utilisation is increased, since insulin stimulates glucose uptake by muscle and inhibits release of fatty acids from adipose tissue. Physical activity... 

Insulin stimulates glucose uptake by muscle and adipose tissue (Table 23-3), where the glucose is converted to glucose 6-phosphate. In the liver, insulin also activates... 

The uptake of glucose by brain, liver, kidneys, erythrocytes, and the islets of Langerhans is unaffected by insulin. However, in muscle and adipose tissues insulin stimulates glucose uptake. Part of this effect results from insulin-induced translocation of molecules of the 509-residue glucose transport protein GLUT4 (Chapter 8) from the cytosol into the plasma membrane where it can function.354-3563 Insulin apparently also increases the rate of synthesis of the transporters. 

In a placebo-controlled study in six patients with type 2 diabetes mellitus thalidomide 150 mg/day for 3 weeks reduced insulin-stimulated glucose uptake by 31% and glycogen synthesis by 48% (1115). However, it had no effect on rates of glycolysis, carbohydrate oxidation, non-oxidative glycolysis, lipolysis, free fatty acid oxidation, or re-esterification. The authors concluded that thalidomide increases insulin resistance in obese patients with type 2 diabetes. 

Szalkowski, D., White-Carrington, S., Berger, J., and Zhang, B. (1995). Antidiabetic Thiazolidinediones Block the Inhibitory Effect of Tumor Necrosis Factor-a on Differentiation, Insulin-Stimulated Glucose Uptake, and Gene Expression in 3T3-L1 Cells. Endocrinology 136, 1474—1481. 

Sweeney, G., Keen, J., Somwar, R., Konrad, D., Garg, R., and Klip, A. 2001. High leptin levels acutely inhibit insulin-stimulated glucose uptake without affecting glucose transporter 4 translocation in 16 rat skeletal muscle cells. Endocrinology 142 4806-4812. 

Amylin is a 37-residue peptide hormone first discovered independently by two research groups in 1987 (78, 79). Amylin is secreted by pancreatic 3-cells at the same time as insulin (in a roughly 100 1 ratio), and it is the major component of diabetes-associated islet amyloid deposits. It inhibits basal and insulin-stimulated glucose uptake as well as glycogen synthesis by soleus muscles (80). Thus, amylin is also known as a diabetes-associated peptide. 

Insulin stimulates glucose uptake in both the musculature and the fatty tissue. Structural modification of STH, with a concomitant enhancement of its activity, is effected by insulin. The storage of amino acids in the muscles is also increased, (s. tab. 3.10)... 

Insulin-stimulated glucose uptake measured during hyperinsulinaemic clamp studies was similar before and after metformin treatment. Thus, the ability of metformin to lower plasma glucose concentration in NIDDM does not appear to be secondary to an improvement in insulin action (Wu et al., 1990). 

Gustavsson, j., Parpal, S., and StrAl-EORS, P. Insulin-stimulated glucose uptake involves the transition of glucose transporters to a caveolae-rich fraction within the plasma membrane implications for type II diabetes. Mol. Med.,... 

In vitro studies [147] on isolated adipocytes from db/db mice treated for 1 week with AS-6 showed an increase in insulin binding (1.4-3.3-fold), basal glucose uptake (17.5%), insulin-stimulated glucose uptake (58%) and basal lipogenesis (3.4-fold greater than in untreated controls). 

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