Periportal and perivenous hepatocytes remain the zonal characteristics in primary culture

Department of Biochemistry A, The Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
Biochemical and Biophysical Research Communications (Impact Factor: 2.3). 10/1986; 139(3):1055-61. DOI: 10.1016/S0006-291X(86)80284-4
Source: PubMed


Periportal and perivenous hepatocytes from rat liver were isolated by combined digitonin-collagenase perfusion, and gluconeogenesis, urea synthesis and fatty acid synthesis was measured both in freshly isolated cells and in primary culture. A periportal zonation of gluconeogenesis and urea synthesis of about 3 and 1.5 fold, respectively, was observed. This zonation persisted unchanged for 23 hours in culture under identical conditions of incubation for periportal and perivenous cells. Fatty acid synthesis was not zonated.

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    ABSTRACT: Isolated rat hepatocytes maintained in primary culture were able to use glucose for glycogen synthesis by both direct and indirect mechanisms. Cells that had been isolated from fed animals and then cultured in the absence of glucose, but in the presence of gluconeogenic substrates such as pyruvate and amino acids, had decreased glycogen contents compared with similar cells that had been cultured in the presence of glucose. Upon reexposure to glucose, the glucose-starved cells showed time-dependent changes in the preferred pathway for the use of glucose for glycogen synthesis. These changes were noted either in the absence or presence of insulin; however, net accumulation of glycogen was observed only in the presence of the hormone.
    No preview · Article · Mar 1988 · Biochemistry and Cell Biology
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    ABSTRACT: We have investigated the cause of defective glycogen synthesis in hepatocyte preparations enriched with cells from the periportal or perivenous zones obtained by the methods of Lindros & Penttila [Biochem. J. (1985) 228, 757-760] and of Quistorff [Biochem. J. (1985) 229, 221-226]. A modified procedure which yields hepatocytes capable of consistent rates of glycogen synthesis is described, and the rates of glucose and glycogen syntheses and of glycolysis in hepatocytes from the two zones are compared. Glycogen synthesis in cells was greatly impaired by very low concentrations (0.01-0.05 mg/ml) of digitonin, which had little effect on glucose and protein syntheses and Trypan Blue exclusion. Cells exposed to such low concentrations of digitonin lose all their synthetic capacity and ability to exclude Trypan Blue when incubated with EGTA, which does not affect cells not exposed to digitonin. With a modified procedure based on this phenomenon, our study reveals that hepatocyte preparations enriched with cells from the periportal zone synthesized glucose from lactate and alanine at rates twice those by cells from the perivenous zone, whereas the rate of glycogen synthesis from C3 precursors in periportal cells was 4 times that in the perivenous preparations. With substrates entering the pathway at the triose phosphate level, gluconeogenesis in periportal-cell preparations was 20% higher, and glycogen synthesis was twice that in perivenous preparations. Glycolysis was studied by the formation of 3HOH from [2-3H]glucose, the yield of lactate, and the conversion of [14C]glucose into [14C]lactate. In cell preparations from both zones glycolysis by all criteria was negligible at 10 mM-glucose, but was substantial at higher concentrations. However, there was no difference between the zones. We confirm that the capacities for glucose and glycogen syntheses in periportal cells are higher than in perivenous cells, but that at physiological glucose concentrations there is negligible glycolysis in liver parenchyma in both zones. The metabolic pattern in the perivenous cells is not glycolytic.
    Preview · Article · Nov 1988 · Biochemical Journal
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    ABSTRACT: Hepatocytes isolated from the periportal or perivenous zones of livers of fed rats were used to study the long-term (14 h) and short-term (2 h) effects of glucagon on gluconeogenesis and ketogenesis. Long-term culture with glucagon (100 nM) resulted in a greater increase (P less than 0.01) in gluconeogenesis in periportal than in perivenous cells (93 +/- 16 versus 30 +/- 14 nmol/h per mg of protein; 72% versus 30% increase), but short-term incubation (2 h) with glucagon resulted in similar stimulation in the two cell populations. Rates of ketogenesis (acetoacetate and D-3-hydroxybutyrate production) were not significantly higher in periportal cells cultured without glucagon, compared with perivenous cells. However, after long-term culture with glucagon, the periportal cells had a significantly higher rate of ketogenesis (from either palmitate or octanoate as substrate), but a lower 3-hydroxybutyrate/acetoacetate production ratio, suggesting a more oxidized mitochondrial NADH/NAD+ redox state despite the higher rate of beta-oxidation. Periportal hepatocytes had a higher activity of carnitine palmitoyltransferase but a lower activity of citrate synthase than did perivenous cells. These findings suggest that: (i) glucagon elicits greater long-term stimulation of gluconeogenesis in periportal than in perivenous hepatocytes maintained in culture; (ii) after culture with glucagon, the rates of ketogenesis and the mitochondrial redox state differ in periportal and perivenous hepatocytes.
    Full-text · Article · Dec 1988 · Biochemical Journal
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