Plasma glucose values after oral glucose challenge vary widely in nondiabetic subjects. We have now evaluated the role of insulin resistance in determining the plasma glucose response to oral glucose in 74 volunteer subjects with normal glucose tolerance. In these subjects, we determined the plasma glucose and insulin responses over a 3-h period to a 75-g oral glucose challenge, and the steady-...

In normal fasted rats whole liver tissue contains as much glucose as the blood plasma, i.e., the ratio of the concentrations is about unity. The concentration of glucose in hepatic intracellular water is about 1.2 times higher than in plasma water. In rats injected with insulin the concentration of glucose in the liver falls to a lesser extent than in the plasma: resulting in a ratio of concent...

The flux ratio for hexokinase type II from rat muscle, i.e. the rate of conversion of glucose 6-phosphate molecules into ATP molecules divided by the simultaneous rate of conversion of glucose 6-phosphate molecules into glucose molecules, increases with the MgATP concentration but is independent of the glucose concentration. This behaviour requires that glucose must bind before MgATP when the r...

The changes in plasma glucose concentration and in interstitial glucose concentration, determined with a miniaturized subcutaneous glucose sensor, were investigated in anesthetized nondiabetic rats. Interstitial glucose was estimated through two different calibration procedures. First, after a glucose load, the magnitude of the increase in interstitial glucose, estimated through a one-point cal...

direct electron transferring of glucose oxidase was investigated   on reduced graphene and graphene oxide templates. the direct electrochemistry   glucose oxidase on   graphene showed a cyclic voltammograms corresponding to the fad/fadh 2   redox couple with an anodic, cathodic and formal potential of -430, -460 and   -445 mv, respectively in 0.1 m phosphate buffer solution and air saturated   ...

Of the factors tested, the source and concentration of carbon and nitrogen in the medium exerted maximum effect on growth and acid production. Glucose (15%) and urea (0.14%) induced glucose oxidase synthesis and optimum yield of calcium gluconate. Potassium dihydrogen phosphate (0.2%) and magnesium sulphate (0.06%) stimulated glucose oxidase activity and calcium gluconate production. Borax at a...

1. Concentrations of cyclic AMP (adenosine 3':5'-cyclic monophosphate) and rates of insulin release were measured in islets of Langerhans isolated from rat pancreas and incubated for various times in the presence of glucose, 3-isobutyl-1-methylxanthine, caffeine, theophylline, adrenaline and diazoxide. 2. Caffeine and theophylline produced small but significant increases in both cyclic AMP and ...

Preexposure to a low concentration of glucose upregulates glucose transport into skeletal muscle, whereas exposure to a high concentration of glucose has the opposite effect. This autoregulatory process occurs independently of insulin, and the mechanism by which it operates is incompletely understood. Activation of the energy-sensing enzyme AMP-activated protein kinase (AMPK) has been shown to ...

A model with two time delays is presented for modeling the insulin secretion ultradian oscillations in the glucose-insulin metabolic system. One delay is for the insulin response time delay (around 6 minutes) to the glucose concentration level increase, and the other is for the hepatic glucose production time delay (around 36 minutes). The results of the analysis of this model are in agreement ...

Membrane transport of glucose and intracellular phosphorylation of the sugar are both accelerated by anoxia in the perfused isolated rat heart (Morgan, Randle & Regen, 1959). In isolated rat diaphragm, membrane transport of glucose is accelerated by anoxia, but the effect of anoxia on glucose phosphorylation in this tissue is not known (Randle & Smith, 1958a, b). Crane & Sols (1953) have shown ...