The fed or absorptive state

Hormone levels are affected when the products of digestion enter the blood. 

The products of digestion enter cells from the blood. 

The fate of glucose in the fed (absorptive) state 1. The fate of glucose in the liver 

The triacylglycerols of chylomicrons (produced from dietary fat) and VLDL (produced from glucose by the liver) are digested in capillaries by lipoprotein lipase to form fatty acids and glycerol. 

The fatty acids are taken up by adipose tissue, converted to triacylglycerols, and stored. 

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The answer is D. This student is still in the fed or absorptive state within 1 hour of a meal, so elevated levels of many nutrients derived from food digestion would be observed in her blood. This would include all items in the list except glucagon. High nutrient levels in the blood evoke increased insulin secretion from the beta cells and suppression of glucagon secretion by the alpha cells of the islets of Langerhans. Therefore, blood levels of glucagon would be decreased relative to other nutritional states. 

The Fed State During a meal, we ingest carbohydrates, lipids, and proteins, which are subsequently digested and absorbed Some of this food is oxidized to meet the immediate energy needs of the body. The amount consumed in excess of the body s energy needs is transported to the fuel depots, where it is stored. During the period from the start of absorption until absorption is completed, we are in the fed, or absorptive, state. Whether a fuel is oxidized or stored in the fed state is determined principally by the concentration of two endocrine hormones in the blood, insulin and glucagon... 

The fed and fasted state may also have significant effects on the absorption or solubility of a compound. Compositions of media that simulate the fed and fasted states can be found in the literature (19) (see also Chapter 5). These media reflect changes in the pH, bile concentrations, and osmolarity after meal intake and therefore have a different composition than that of typical compendial media. They are primarily used to establish in vitro-in vivo correlations during formulation development and to assess potential food effects and are not intended for quality control purposes. For quality control purposes, the substitution of natural surfactants (bile components) with appropriate synthetic surfactants is permitted and encouraged because of the expense of the natural substances and the labor-intensive preparation of the biorelevant media. 

There was no difference in rate or extent of absorption of amlodipine capsules between the fed and fasted state in a study in healthy subjects. ... 

Following oral administration, approximately 75% of an administered ketoconazole dose is absorbed. However, there is considerable inter- and intrapatient variation, with oral absorption impaired when gastric acidity is decreased due to clinical pathology, e.g. achlorhydria, or due to concurrent administration of agents that decrease gastric acidity, e.g. antacids, H2-receptor antagonists or proton pump inhibitors, or whether the patient is in a fed or fasted state (absorption is enhanced in the fed state). 

Under normal feeding patterns the rate of tissue protein catabolism is more or less constant throughout the day it is only in cachexia that there is an increased rate of protein catabolism. There is net protein catabolism in the postabsorptive phase of the feeding cycle and net protein synthesis in the absorptive phase, when the rate of synthesis increases by about 20-25%. The increased rate of protein synthesis is, again, a response to insulin action. Protein synthesis is an energy-expensive process, accounting for up to almost 20% of energy expenditure in the fed state, when there is an ample supply of amino acids from the diet, but under 9% in the starved state. 

The important stages in delivering a drug to its desired target after an oral dose can be summarized as shown in Fig. 6.2. Initially the formulation has to be swallowed and survive the transition to the site of absorption - the gastrointestinal tract (GIT). The time required for this to happen will depend on the stomach emptying time, which in turn will be a function of the fed/fasted state of the subject or animal that is being studied (see for example Ref. [7]). This kind of information can only be obtained from in vivo studies. 

Figure 5-4. Metabolic activities of major organs in the fed state. The relative activities of major metabolic pathways or processes in each of the organs are indicated by their font sizes. The exchange of nutrient materials and fuel molecules through the bloodstream illustrates the interrelationships of these organs. In the absorptive condition, all organs share the bounty of nutrients made available by digestion of food by the intestine. PPP, pentose phosphate pathway FA, fatty acids TAG, triacyl-glycerol.

For the detemlnaticn of Q-a, the solution or the suspension of the catedyst is pr >ared in an aerated 4.5 1 vessel, vAiich is cogitated by a six-blade tuid ine. After adjusting pH, aeration rate aid stirring speed, a constant rate of hydrazine is fed into the reactor. At steatfy state the feed rate of hydrazine n is equail to the absorption rate of oo gen no2, as written in ei (2) ... 

THE FED STATE Two to four hours after a meal, the body is in the absorptive (fed) state. This is a period of anabolism, where there is a high insulin gfucagon ratio in the circulation. In the liver, glycolysis is increased, and glycogen synthesis is favoured. There is no gluconeogenesis. Surplus amino acids are used for protein synthesis or deaminated in the liver to pyruvate, acetyl CoA or oxaloacetate, which enter the TCA cycle. FA synthesis is favoured sinc e excess acetyl CoA is converted to malonyl CoA (by acetyl CoA carboxylase). Malonyl CoA inhibits the carnitine shuttle which transports FAs to be oxidized in the mitochondria, therefore they have to be stored as TAG in the periphery. 

During the absorptive or fed state (up to 2-4 hours after a meal), metabolic events in the body allow processing of the food-derived compounds (Figure 5-4). 

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