Insulin sources

Endothelial cells are the major source of ET-1-synthesis. ET-1 is also produced by astrocytes, neurons, hepatocytes, bronchial epithelial cells, renal epithelial and mesangial cells. Physiological stimuli of ET-1-synthesis in endothelial cells are angiotensin II, catecholamines, thrombin, growth factors, insulin, hypoxia and shear stress. Inhibitors of ET-1 synthesis are atrial natriuretic peptide, prostaglandin E2 and prostacyclin. ET-2 is mainly synthesized in kidney, intestine, myocardium and placenta and ET-3 is predominantely produced by neurons, astrocytes and renal epithelial cells. 

Insulin is available as purified extracts from beef and pork pancreas and is biologically similar to human insulin. However, these animal source insulins are used less frequently today than in years past. They are being replaced by synthetic insulins, including human insulin or insulin analogy. 

Human insulin is derived from a biosynthetic process using strains of Escherichia coli (recombinant DNA, rDNA). Human insulin appears to cause fewer allergic reactions than does insulin obtained from animal sources. Insulin analogy, insulin lispro, and insulin aspart are newer forms of human insulin made by using recombinant DNA technology and are structurally similar to human insulin. 

Insulin is available in concentrations of U100 and U500. The nurse must read the label of die insulin bottle carefully for the name, source of insulin (eg, human, beef, pork, beef and pork, purified beef), and die number of units per milliliter (U/ mL). The dose of insulin is measured in units (U). U100 insulin has 100 units in each milliliter U500 has 500 units in each milliliter. Most people with diabetes use the U100 concentration. Fhtients who are resistant to insulin and require large insulin doses require the U500 concentration. 

Insulin—types how dosage is expressed calculating die insulin dosage importance of using only die type, source, and brand name recommended by die health care provider importance of not changing brands unless the health care provider approves keeping a spare vial on hand prescription for insulin purchase not required. 

Strict avoidance of hypoglycemia. Ensure an adequate source of dextrose in any patient receiving an insulin product... 

Insulin is the one agent that can be used in all forms of DM for blood sugar control. Insulin is the essential treatment for patients with type 1 DM and can overcome insulin resistance in patients with type 2 DM. Insulin is available commercially in various formulations that vary markedly in terms of onset and duration of action and the source from which a product is obtained. Insulins can be divided into four separate classes based on their length of action. Most formulations are available as U-100, indicating a concentration of 100 units/mL. Insulin is typically refrigerated, and most vials are good for 28 days at room temperature. Specific details of insulin products are listed in Table 40-9. 

Since erythrocytes, platelets, and leukocytes have received the greatest attention, the discussion that follows will be limited to these carriers. Fibroblasts [180] and hepatocytes [181] have been specifically used as viable sources to deliver missing enzymes in the management of enzyme-deficiency diseases, whereas islets are useful as a cellular transplant to produce insulin [182,183],... 

Insulin. Insulin is a peptide hormone produced by P-cells of the islets of Langerhans. It is an important anabolic hormone secreted at times when the concentration of nutrient molecules in the blood is high, such as periods following a meal. Its overall effects include allowing the body to use carbohydrates as an energy source and to store nutrient molecules. Specifically, insulin exerts its important actions on the following tissues ... 

Online LC-ESI-TOF-MS experiments are carried out in a very similar fashion to the off-line NPS-HPLC separations described above, with a few notable exceptions. Firstly, 0.3% (v/v) formic acid is added to each mobile phase to counteract the ionization suppression induced by TFA. Because of the formic acid UV detection must be carried out at 280 nm (as opposed to 214 nm). To aid in normalization between runs 1 jag of Bovine insulin (MW = 5734 Da) is added to each chromatofocusing fraction prior to injection onto the column. Finally, the flow is split postcolumn directing 200 JlL/min into the ion source and the remaining 300 JlL/min through the UV detector and fraction collection. 

Availability. Some 170 million people suffer from diabetes worldwide, a figure projected to double by 2030. Insulin administration is essential to the survival of those with type-1 (insulin-dependent) diabetes, and is required to control the progression of a minority of those with (the more common) insulin-independent type-2 diabetes. The annual insulin requirement has surpassed 5000 kg and continues to grow, prompting concern of an insulin shortfall from slaughterhouse sources. 

Insulin, whatever its source, may be formulated in a number of ways, generally in order to alter its pharmacokinetic profile. Fast (short)-acting insulins are those preparations that yield an elevated blood insulin concentration relatively quickly after their administration (which is usually by s.c. or, less commonly, by i.m. injection). Slow-acting insulins, on the other hand, enter the circulation... 

Glycerol is a non-insulin-dependent source of carbohydrate that can be used to avoid stress-related hyperglycemia in critically ill patients. A major disadvantage of the available glycerol solution is the dilute concentration... 

Insulin, a hormone produced by the pancreas, is essential for the metabolism of glucose, proteins, and fats. Insulins are classified on the basis of the duration of action as rapid-, intermediate-, or long-acting and on the basis of source or species, such as human or animal (beef, pork, and mixtures of beef and pork). Table 10.1 summarizes insulin preparations currendy available in the United States. 

Insulin was originally (since the 1930s) obtained from porcine and bovine extracts. Bovine insulin differs from human insulin by three amino acids, and it can elicit an antibody response that reduces its effectiveness. Porcine insulin, however, differs in only one amino acid. An enzymatic process can yield insulin identical to the human form. Currently, insulin is produced via the rDNA process it was the first recombinant biopharmaceutical approved by the FDA in 1982. The recombinant insulin removes the reliance on animal sources of insulin and ensures that reliable and consistent insulin is manufactured under controlled manufacturing processes. A description of diabetes meUitus and insulin is presented in Exhibit 4.13. 

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