Cytophotometric analysis of alkaline phosphatase and 5′‐nucleotidase activity in regenerating rat liver after partial hepatectomy

Noorden, C. J. F. Van; Vogels, I. M. C.; Houtkooper, Joop M.

doi:10.1002/cbf.290060109

Cited by 19 publications

(6 citation statements)

References 41 publications

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“…1). This phenomenon is similar to that observed in rats after PHx (60,78). These results suggest that the first 48 h might be critical for biliary tract integrity and biliary excretion to maintain normal concentrations of BAs in liver, especially before the BA pool decreases.…”

Section: Effects Of Phx On Plasma Alp Alt and Conjugated Bilirubin supporting

confidence: 87%

Role of hepatic transporters in prevention of bile acid toxicity after partial hepatectomy in mice

Csanaky¹,

Aleksunes²,

Tanaka³

et al. 2009

American Journal of Physiology-Gastrointestinal and Liver Physi

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The enterohepatic recirculation of bile acids (BAs) is important in several physiological processes. Although there has been considerable research on liver regeneration after two-thirds partial hepatectomy (PHx), little is known about how the liver protects itself against BA toxicity during regeneration. In this study, various BAs in plasma and liver, the composition of micelle-forming bile constituents, as well as gene expression of the main hepatobiliary transporters were quantified in sham-operated and PHx mice 24 and 48 h after surgery. PHx did not influence the hepatic concentrations of taurine-conjugated BAs (T-BA) but increased the concentration of glycine-conjugated (G-BA) and unconjugated BAs. Total BA excretion (microg x min(-1) x g liver wt(-1)) increased 2.4-fold and was accompanied by a 55% increase in bile flow after PHx. The plasma concentrations of T-BAs (402-fold), G-BAs (17-fold), and unconjugated BAs (500-fold) increased. The mRNA and protein levels of the BA uptake transporter Ntcp were unchanged after PHx, whereas the canalicular Bsep protein increased twofold at 48 h. The basolateral efflux transporter Mrp3 was induced at the mRNA (2.6-fold) and protein (3.1-fold) levels after PHx, which may contribute to elevated plasma BA and bilirubin levels. Biliary phospholipid excretion was nearly doubled in PHx mice, most likely owing to increased mRNA expression of the phospholipid transporter, Mdr2. In conclusion, the remnant liver after PHx excretes 2.5-fold more BAs and three times more phospholipids per gram liver than the sham-operated mouse liver. Upregulation of phospholipid transport may be important in protecting the biliary tract from BA toxicity during PHx.

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Section: Effects Of Phx On Plasma Alp Alt and Conjugated Bilirubin supporting

confidence: 87%

Role of hepatic transporters in prevention of bile acid toxicity after partial hepatectomy in mice

Csanaky¹,

Aleksunes²,

Tanaka³

et al. 2009

American Journal of Physiology-Gastrointestinal and Liver Physi

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“…The present study shows that PVA added to the Wachstein-Meisel medium for the demonstration of 5'-nucleotidase activity results in an accurate localization at bile canalicular and sinusoidal plasma membranes of liver parenchymal cells as well as in plasma membranes of endothelial cells lining central veins and in fibroblasts present in portal tracts. The localization in parenchymal cells is in agreement with data obtained from rat liver using formaldehyde-fixed sections and aqueous incubation media (Hardonk, 1968;Van Noorden et al, 1987), lipid-extracted sections (Hardonk et al, 1977) and freeze-substituted paraffin-embedded sections (Klaushofer & Von Mayersbach, 1977. The localization at the plasma membranes of endothelial cells and in fibroblasts has been described only at the ultrastructural level (Berman et al, 1980).…”

Section: Discussionsupporting

confidence: 72%

“…The production of adenosine and a function in the control of the blood flow has been suggested (Arch & Newsholme, 1978). Another more favourable hypothesis is that the enzyme is related to the breakdown of nucleic acids, especially messenger RNA (Hardonk & De Boer, 1968;Yannarell & Aronson, 1973;Van Noorden et al, 1987). Synthesis of proteins takes place mainly periportally (Tuczek et al, 1985), where the lowest 5'-nucleotidase activity also occurs.…”

Section: Discussionmentioning

confidence: 97%

A quantitative histochemical study of 5′-nucleotidase activity in rat liver using the lead salt method and polyvinyl alcohol

Frederiks

Marx

1988

Histochem J

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5'-Nucleotidase (EC 3.1.3.5) activity was demonstrated in cryostat sections of rat liver using the Wachstein-Meisel medium and polyvinyl alcohol as tissue stabilizer. Optimum activity was obtained using an incubation medium containing 5 mM AMP, 10 mM magnesium chloride, 7.2 mM lead nitrate, 0.1 M Tris-maleate buffer, pH 7.2, and 17% (w/v) polyvinyl alcohol (Sigma, type III). The activity was localized at the bile canalicular and sinusoidal side of the plasma membranes of liver parenchymal cells as well as in the plasma membranes of endothelial cells of central veins and in fibroblasts surrounding portal tracts. The reaction was specific for 5'-nucleotidase because it was inhibited by ADP. Alkaline phosphatase did not interfere in the reaction. Cytophotometric analysis revealed a linear relationship between the formation of the final reaction product and incubation times up to 20 min and section thicknesses up to 8 micron. The activity in pericentral zones was 1.35 times the activity in periportal zones. The Michaelis constant for AMP was 1.4 mM in pericentral zones and 0.8 mM in periportal zones, suggesting that the bile canalicular and sinusoidal enzymes differ in their kinetic characteristics.

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“…The distribution of AlkP in Wistar rat liver is in keeping with the histochemical literature on the enzyme, independently of the method used for its visualization, that is the indoxyltetrazolium salt method used in the present research, 35,43,44 the metal capture method or the simultaneous coupling method. 36,37,45 However, as far as large bile ducts are concerned, our data disagree with data reported on reviews, 38,46 according to which in the rat AlkP is expressed by large interlobular bile ducts but not by small bile ducts.…”

Section: Discussionsupporting

confidence: 74%

Altered alkaline phosphatase activity in obese Zucker rats liver respect to lean Zucker and Wistar rats discussed in terms of all putative roles ascribed to the enzyme

et al. 2011

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Biliary complications often lead to acute and chronic liver injury after orthotopic liver transplantation (OLT). Bile composition and secretion depend on the integrated action of all the components of the biliary tree, starting from hepatocytes. Fatty livers are often discarded as grafts for OLT, since they are extremely vulnerable to conventional cold storage (CS). However, the insufficiency of donors has stimulated research to improve the usage of such marginal organs as well as grafts. Our group has recently developed a machine perfusion system at subnormothermic temperature (20°C; MP20) that allows a marked improvement in preservation of fatty and even of normal rat livers as compared with CS. We sought to evaluate the response of the biliary tree of fatty liver to MP20, and a suitable marker was essential to this purpose. Alkaline phosphatase (AlkP, EC 3.1.3.1), frequently used as marker of membrane transport in hepatocytes and bile ducts, was our first choice. Since no histochemical data were available on AlkP distribution and activity in fatty liver, we have first settled to investigate AlkP activity in the steatotic liver of fatty Zucker rats (fa/fa), using as controls lean Zucker (fa/+) and normal Wistar rats. The AlkP reaction in Wistar rats was in accordance with the existing data and, in particular, was present in bile canaliculi of hepatocytes in the periportal region and midzone, in the canals of Hering and in small bile ducts but not in large bile ducts. In lean ZR liver the AlkP reaction in Hering canals and small bile ducts was similar to Wistar rat liver but hepatocytes had lower canalicular activity and besides presented moderate basolateral reaction. The difference between lean Zucker and Wistar rats, both phenotypically normal animals, could be related to the fact that lean Zucker rats are genotypically heterozygous for a recessive mutated allele. In fatty liver, the activity in ductules and small bile ducts was unchanged, but most hepatocytes were devoid of AlkP activity with the exception of clusters of macrosteatotic hepatocytes in the mid-zone, where the reaction was intense in basolateral domains and in distorted canaliculi, a typical pattern of cholestasis. The interpretation of these data was hindered by the fact that the physiological role of AlkP is still under debate. In the present study, the various functions proposed for the role of the enzyme in bile canaliculi and in cholangiocytes are reviewed. Independently of the AlkP role, our data suggest that AlkP does not seem to be a reliable marker to study the initial step of bile production during OLT of fatty livers, but may still be used to investigate the behaviour of bile ductules and small bile ducts.

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Cytophotometric analysis of alkaline phosphatase and 5′‐nucleotidase activity in regenerating rat liver after partial hepatectomy

Cited by 19 publications

References 41 publications

Role of hepatic transporters in prevention of bile acid toxicity after partial hepatectomy in mice

Role of hepatic transporters in prevention of bile acid toxicity after partial hepatectomy in mice

A quantitative histochemical study of 5′-nucleotidase activity in rat liver using the lead salt method and polyvinyl alcohol

Altered alkaline phosphatase activity in obese Zucker rats liver respect to lean Zucker and Wistar rats discussed in terms of all putative roles ascribed to the enzyme

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