Lipases serum

Difference bolwL cn Hormone Sensitive i.ipasc and 1 ipoproleui Lipase Serum Albumin arut the Transport of Fatly Acids... 

Difference between Hormone-Sensitive Lipase and Lipoprotein Lipase Serum Albumin and the Transport of Fatty Acids... 

Sample Collection and Enzyme Stability. Serum samples are collected with chemically clean, sterile glassware. Blood is allowed to clot at room temperature, the clot is gently separated from the test tube with an applicator stick, and the blood is centrifuged for 10 minutes at 1,000 g. If the red cells are known to contain the enzymes whose activity is being measured, as in the case of LD, even slightly hemolyzed serums must be discarded. When acid phosphatase is to be measured, the serum should be placed immediately in ice and processed as soon as possible, or it should be acidified by the addition of a small amount of sodium citrate. Anticoagulants such as EDTA, fluoride and oxalate inhibit some serum enzymes. However, heparin activates serum lipoprotein lipase. 

Numerous workers have found that measurements of serum lipase activity are useful in the diagnosis of pancreatitis (83, 84, 85). Despite this, serum lipase determinations are not usually performed in clinical laboratories, probably due to inherent problems associated with the conventional methods, based on an emulsified lipid substrate. The methods are also not very suitable for manual batch analysis nor for automation due to laborious post incubation procedures. 

Cherry and Crandall in 1932 (86) used olive oil as substrate with gum acacia as the emufsTfier. This method has served as the basis for a number of modifications that increased the stability of the emulsion, decreased incubation time and gave better precision. When a serum sample is incubated with a stabilized olive oil emulsion, lipase acts at the interface of substrate and water to hydrolyze olive oil into fatty acid plus diglycerides, and to a small extent to monoglycerides and glycerol. The bile salt sodium deoxycholate activates the reaction. These methods measure the liberated fatty acids by titration with a standardized NaOH solution. An indicator such as phenolphatalein, thymolphthalein or methyl red or a pH meter are used to detect the end point. 

Lippi et. al (87) and Dirstine (88) circumvented titration by converting the liberated fatty acids into copper salts, which after extraction in chloroform are reacted with diethyldithio-carbamate to form a colored complex which is measured photometrically. While the end point appears to be more sensitive than the pH end point determination, the advantages are outweighed by the additional steps of solvent extraction, centrifugation and incomplete extraction when low concentrations of copper salts are present. Other substrates used for the measurement of lipase activity have been tributyrin ( ), phenyl laurate (90), p-nit ro-pheny1-stearate and 3-naphthyl laurate (91). It has been shown that these substrates are hydrolyzed by esterases and thus lack specificity for lipase. Studies on patients with pancreatitis indicate olive oil emulsion is definitely superior to water soluble esters as substrates for measuring serum lipase activity. 

Several tubidimetric methods (92, 93) have been described specifically for the kinetic determination of lipase in serum but these methods suffer from lack of linearity with increasing enzyme concentration, and instability of emulsions. 

Song, H. Tietz, N. W. and Tan, C. Usefulness of serum lipase, esterase and amylase estimation in the diagnosis of pancreatitis - a comparison. Clin. 

Lippi, U. Stevanato, 6. and Guidi, G. A rapid photometric micromethod for serum lipase determination. Clin. Chim. Acta (1972), 37, 199-202. 

Saifer, A. and Perle, G. Photometric micro determination of serum lipase with a phenyl laurate substrate. 

Yang, J. S. and Biggs, H. G. Rapid, reliable method for measuring serum lipase activity. Clin. Chem. (1971),... 

Vogel, W. C. and Zieve, L. A rapid and sensitive turbidimetric method for serum lipase based upon differences between lipases of normal and pancreatitis serum. Clin. Chem. (1963), , 168-181. 

As acute pancreatitis progresses, the serum lipase can also become elevated.2... 

Diagnosis of acute pancreatitis is based on the patient s history and presenting signs and symptoms. Evaluation of laboratory results, specifically the serum amylase and lipase, aids in diagnosis. Serum amylase is elevated early in the disease process but may return to normal within 12 hours.10 Serum lipase will remain elevated for days after the acute event and may lend itself more to the diagnosis depending on when the patient presents for evaluation.11... 

The goals of treatment for acute pancreatitis include (1) resolution of nausea, vomiting, abdominal pain, and fever (2) ability to tolerate oral intake (3) normalization of serum amylase, lipase, and white blood cell count and (4) resolution of abscess, pseudocyst, or fluid collection as measured by CT scan. 

Serum amylase and lipase levels are not usually elevated in chronic pancreatitis. 

Sorafenib is a multikinase inhibitor that inhibits both intracellular and extracellular kinases to decrease renal cell cancer proliferation. The half-life of sorafenib is 25 to 48 hours, with a bioavailability of 38% to 49% and a time to peak concentration of 3 hours. Sorafenib is metabolized primarily by the liver by CYP450 3A4. Sorafenib is used for the treatment of renal cell cancer. The primary side effects of sorafenib include rash, hand-foot skin reaction, diarrhea, pruritus, and elevations in serum lipase. 

J5. Jaume, J. C., Mendel, C. M Frost, P. H., Greenspan, F. S and Laughton, C. W., Extremely low doses of heparin release lipase activity into plasma and can thereby cause artifactual elevations in serum free thyroxine concentration as measured by equilibrium dialysis. Thyroid 6, 79-84 (1996). 

Acute pancreatitis (AP) is an inflammatory disorder of the pancreas characterized by severe pain in the upper abdomen and increased serum concentrations of pancreatic lipase and amylase. 

Serum lipase is specific to the pancreas, and concentrations are usually elevated. The increases persist longer than serum amylase elevations and can be detected after the amylase has returned to normal. 

Serum amylase and lipase concentrations usually remain normal unless the pancreatic duct is blocked or a pseudocyst is present. 

The serum CES was purified to homogeneity to determine its contribution to pyrethroid metabolism in the rat [30]. Both trans-permethrin and bioresmethrin were effectively cleaved by this serum CES, but deltamethrin, esfenvalerate, a-cypermethrin, and m-permethrin were slowly hydrolyzed. Two model lipases produced no hydrolysis products from pyrethroids. These results demonstrated that extrahepatic esterolytic metabolism of specific pyrethroids might be significant. 

The range of values for this enzyme corresponds to 0.0 to 1.5 ml. A//20 sodium hydroxide required to neutralize the fat acids released by 1 ml. of serum under controlled conditions.18 Since 0.05 ml. of AV20 sodium hydroxide solution should be easily detectable, this corresponds to at least a 30-fold range and is in line with the large range in the blood lipids which is known to be inter-individual (p. 58). Because of lack of interest in the question, apparently no investigation has been made regarding the constancy or lack of constancy of the lipases in the blood of specific individuals. 

See also research, medical biochemical individuality and, 206-207 metabolism, 203 variations, exceptions and, 202 vision, 202-203 vitamin research and, 204-205 scopolamine, 228 scurvy, 167-168 self-esteem, genetics and, 16 self-selection of foods, 180 Selye, Hans, 230 senile dementia, 34-35, 227, 230 sensory physiology and psychology, 205 serotonin, 236 serum amylase, 80-81 serum lipase, 81 serum phenol sulfatase, 81 sex behavior, 100, 104-105 psychiatry and, 231 sex differences... 

Serum lipase is synthesized and stored in the granules of pancreatic acinar cells and is excreted from the apical poles of the acinar cells into the duct system of the gland. Lipases are produced not only in the pancreas but also at various sites in the human digestive tract [126][127]. Lipases are also found in leucocytes, adipose tissue, lung, and milk. 

Rare genetic absence of lipoprotein lipase results in excess triglyceride in the blood and its deposition in several tissues, including liver, skin, and pancreas. Orange-red eruptive xanthomas over the mucous membranes and skin may be seen. Abdominal pain and acute pancreatitis may occur. Fasting chylomicronemia produces a milky turbidity in the serum or plasma. 

Opiates can effect serum levels of enzymes and other substances whose homeostatic control depends on clearance through the liver (F8, G12, M15, N4, S19). In one reported case, the aspartate aminotransferase was within normal limits before the administration of codeine, but within 2 hours after the drug, the enzyme activity had risen to two times the normal value by 8 hours to eight times the normal activity, and within 24 hours it had returned to normal (F8). Increases in transaminase to levels 5-85 times the control value have been reported in 6 of 16 patients with disease of the biliary tree following the administration of codeine phosphate (2 grains) (B7, F8). Gross has shown that morphine, codeine, or mepheridine administration produce elevations of serum amylase or lipase (G12). These elevations have been attributed to constriction of the sphincter of Oddi and increased intraductal pressure on the pancreatic duct (G12, N4). 

G12. Gross, J. B., Comfort, M. W., Mathieso, D. R., and Power, M. H., Elevated values of serum amylase and lipase following administration of opiates. Proc. Staff Meet. Mayo Clin. 28, 81-87 (1951). 

Lipoprotein lipase, an enzyme responsible for the hydrolysis of the triglyceride moiety of lipoproteins, has been shown to be activated by serum high-density lipoproteins (B4, K5, S6, S14), by very low density... 

F3. Fielding, C. J., Lim, C. T., and Scanu, A. M., A protein component of serum high density lipoprotein with cofactor activity against purified lipoprotein lipase. Biochem. Biophys. Res. Commun. 39, 889-894 (1970). 

G2. Ganesan, D., Bradford, R. H., Alaupovic, P., and McConathy, W. J., Differential activation of lipoprotein lipase form human post-heparin plasma, milk and adipose tissue by polypeptides of human serum apolipoprotein C. FEBS (Fed. Eur. Biochem. Soc.), Lett. 15, 205-208 (1971). 

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