Alkaline phosphatase intestinal type

Alkaline phosphatase (Sigma Type VII-NT, from bovine intestinal mucosa, 3Afsodium chloride solution, 5000 U)... 

The type of inhibition of chicken intestine alkaline phosphatase by forphenicine was not competitive, but uncompetitive with the stibstrate. Its derivative, forphenicinol, which contains a hydroxymethyl grorp instead of the formyl group in the forphenicine molecule, did not inhibit alkaline phosphatase but, it did bind to cells. Forphenicinol enhanced delayed-type lOT>ersensiti-vity (13,14) and the phagocytic activity of macrophages. 

Perhaps the most characteristic feature of alkaline phosphatase is the way in which the pH optimum changes with increasing substrate concentration. A typical set of curves for calf intestinal phosphatase and phenyl phosphate is given in Fig. 1. Other examples of this type of behavior are found with -glycerophosphate and chicken intestinal... 

Alkaline phosphatase (EC 3-1.3-1) Sigma type VII from calf intestine at pH 10.5 was equilibrated with a mix in Eq. 2 at 25°C for 30 min. The 31p NMR spectrum was recorded at pH 8.10. There was no R-l-P left and there were three Pj s found containing and The integration and lack of detectable... 

GGT does not nsnally form part of the standard LFTs in most laboratories. It is an enzyme fonnd in hepatocytes and biliary epithelial cells, and also in kidney, pancreas, intestine and prostate. It has a higher sensitivity for indicating a problem of liver origin than alkaline phosphatase, but tends to follow a similar pattern. It is released in all types of liver dysfunction and therefore cannot generally be used to differentiate between types. However, a raised GGT with an isolated raised alkaline phosphatase can be suggestive of cholestasis. GGT levels can be ten to 20 times normal in cholestatic disease. 

Nuyts GD, Roels FIA, Verpooten GF, Bernard AM, Lauwerys RR, De Broe ME. Intestinal type alkaline phosphatase in urine as an indicator of mercury induced effects on the S3 segment ofthe proximal tubule. Nephrol Dial Transplant 1992 7 225-229. 

Intestinal-type alkaline phosphatase is specifically located in the S3-segment of the proximal tubuli [73]. Urinary intestinal-type alkaline phosphatase activity is significantly higher in the Cd-exposed subjects than in the non-exposed subjects [74]. The relationship between p2-microglobulin and intestinal-type alkahne phosphatase can be fit to a fourth-order mathematical function. The p2-microglobulin level corresponding to the inflexion point of intestinal-type alkaline phosphatase activity is smaller than that for N-acetyl-p-D-... 

Verpooten GL, Nouwen EJ, Hoylaerts ML, Hendrix PG, De Broe ME. Segment-specific localization of intestinal-type alkaline phosphatase in human kidney. Kidney Int 1989 36 617-625. 

A biochemical evalution of human alkaline phosphatase is postponed until the above considerations have been presented. In our view, the most reasonable analytical approach is based on the measurement of L-phenyl-alanine-sensitive and -insensitive moieties along with their respective heat stabilities. To this may be added information gathered from starch-gel electrophoresis with native and heated serum and from the presence of L-phenylalanine-sensitive bands on the gels following electrophoresis. Experiments of a different type can be included, in which the serum is incubated with neuraminidase and susceptibility of the glycoprotein is established following electrophoresis. Finally, the data on L-phenyl-alanine inhibition of heat-sensitive and -insensitive moieties appear to make sense, if the population of normal subjects is divided into one with the slow-moving intestinal band and one without it. It is from this consideration and other indirect and direct inferences that the intestine is... 

The L-phenylalanine inhibition of rat (G5) or of (Fig. 12) human intestinal alkaline phosphatase and of human placental (G6) enzyme is of the uncompetitive type, because the double reciprocal plots of velocity and substrate concentration were all straight lines parallel to those obtained without the inhibitor. Consequently, the extent of the inhibition was greatly dependent on substrate (Fig. 11) and inhibitor concentrations (Fig. 10). Detailed studies have appeared elsewhere (G5). 

In Table 10 (Parts I and II) are listed the data on the partition of serum alkaline phosphatase for 33 normal subjects according to blood type and status of the slow intestinal band. A statistical analysis appears in Table 11. 

Since there is no difference in the amount of alkaline phosphatase in the intestinal mucosa of subjects of various blood types and secretor status (L2) and since this enzyme is presumed to be L-phenylalanine-sensitive (L14), then the difference in the relative amount of heat-stable LPSAP in persons with or without the slow band may relate to events... 

Often there is no good clinical test available to determine the exact type of hepatic lesion, short of liver biopsy. There are certain patterns of enzyme elevation that have been identified and can be helpful (Table 38-3). ° The specificity of any serum enzyme depends on the distribution of that enzyme in the body. Alkaline phosphatase is found in the bile duct epithelium, bone, and intestinal and kidney cells. 5-Nucleotidase is more specific for hepatic disease than alkaline phosphatase, because most of the body s store of 5 -nucleotidase is in the liver. Glutamate dehydrogenase is a good indicator of centrolobular necrosis because it is found primarily in centrolobular mitochondria. Most hepatic cells have extremely high concentrations of transaminases. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are commonly measured. Because of their high concentrations and easy liberation from the hepato-cyte cytoplasm, AST and ALT are very sensitive indicators of necrotic lesions within the liver. After an acute hepatic lesion is established, it may take weeks for these concentrations to return to normal. ... 

Choriocarcinoma-like differentiation may also be present in otherwise usual-type adenocarcinomas. These foci usually stain with beta-human chorionic gonadotropin (f5-hCG) and placental alkaline phosphatase. (1-hCG staining of usual-type intestinal or signet-ring adenocarcinomas is common approximately 33% stain strongly with polyclonal f5-hCG and 60% are immunoreactive with the monoclonal antibody. " ... 

Saheki, S. et ah. Intestinal type alkaline-phosphatase hyperphosphatasemia associated with liver-cirrhosis, Clin. Chim. Acta, 210, 63, 1992. 

---