Rat liver alkaline phosphatases

Hatoff, David E.; Toyota, Norio; Wong, Caine W.; Miller, A. T.; Takeya, Motohiro; Miyai, Katsumi

doi:10.1007/bf01320264

Cited by 22 publications

(3 citation statements)

References 27 publications

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“…50 It is worth recalling that whereas human liver AlkP activity occurs in the sinusoid and, to a lesser extent, biliary pole of hepatocytes, 51 in rat liver activity is mainly localized in the canalicular membrane of hepatocytes and in portal triad blood vessels. 52 …”

Section: Discussionmentioning

confidence: 99%

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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Section: Discussionmentioning

confidence: 99%

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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“…In patients with PBC, the elevated level of ALP and 5'-NT has been noted to be associated with the higher plasma level of phosphatidylcholines [15,16]. Orthophosphate, glycerol, palmitic, and oleic fatty acids are the base of lecithin's (PhLs) in PBC [17]. The formation of orthophosphate is known to depend on the activity of the enzymes ALP and 5'-NT involved in the hydrolysis of phosphomonoesters.…”

Section: Activity Of Alp γ-Gt 5'-nt and Lap In Pbcmentioning

confidence: 99%

“…These patients also have a low degree of hepatic steatosis [51,55]. This is promoted by the malabsorption of fats due to insufficient intake of bile acids into the intestine and developing steatorrhea [2,17]. Along with this, inhibition of lipogenesis and activation of oxidation of free fatty acids is observed, which is associated with high expression of FGF19 [77].…”

Section: Knowledge Of the Physicochemical Properties Of Lipids And Th...mentioning

confidence: 99%

Pathophysiology of biochemical signs of primary biliary cholangitis

Reshetnyak,

Maev

2023

Explor Dig Dis

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Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is a rare chronic autoimmune cholestatic liver disease, affecting mostly females. With PBС develops chronic cholangiopathy, this is accompanied by the development of gradually progressive liver fibrosis, which leads to intrahepatic cholestasis. Defects in autoimmune tolerance are critical factors in the emergence of the disease. Biochemical signs in PBС appear already in the asymptomatic stage of the disease and they are associated with a disturbance of the secretion of bile acids. Understanding the pathophysiological mechanisms of these signs is essential to both the early diagnosis and treatment of PBC. Early diagnosis of the disease contributes to its more effective treatment. There are many scientifically based modern data on the pathophysiology of clinical and laboratory signs developing in PBС. The purpose of this review is to summarize the data available in the literature and those obtained by the authors on the mechanisms for the development of biochemical criteria for PBC and their diagnostic significance. The opportunity to present the pathophysiological mechanisms of the development of biochemical signs in patients with PBC is associated with the success in the development of modern research methods in biochemistry, molecular biology, and genetics.

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Serum alkaline phosphatase-another piece is added to the puzzle

Kaplan

1986

Hepatology

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Rat liver alkaline phosphatases

Cited by 22 publications

References 27 publications

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

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

Pathophysiology of biochemical signs of primary biliary cholangitis

Serum alkaline phosphatase-another piece is added to the puzzle

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