Gross structural changes in isolated liver cell plasma membranes upon binding of insulin

Biochemistry ◽  
1979 ◽  
Vol 18 (3) ◽  
pp. 445-450 ◽  
Author(s):  
P. Luly ◽  
M. Shinitzky
Keyword(s):  
Liver Cell ◽  
Plasma Membranes ◽  
Structural Changes ◽  
Cell Plasma ◽  
Isolated Liver

scholarly journals Characterization of the binding of diadenosine 5′,5‴-P1,P4-tetraphosphate (Ap4A) to rat liver cell membranes

1996 ◽  
Vol 314 (2) ◽  
pp. 687-693 ◽  
Author(s):  
Mandy EDGECOMBE ◽  
Alexander G. McLENNAN ◽  
Michael J. FISHER
Keyword(s):  
Plasma Membrane ◽  
Rat Liver ◽  
Liver Cell ◽  
Plasma Membranes ◽  
Rank Order ◽  
Liver Cells ◽  
Diadenosine Polyphosphates ◽  
Cell Plasma ◽  
Isolated Liver Cells ◽  
Isolated Liver

Diadenosine polyphosphates present in the extracellular environment can, through interaction with appropriate purinoceptors, influence a range of cellular activities. Here we have investigated the nature of the ligand:receptor interactions involved in diadenosine 5′,5″-P1,P4-tetraphosphate (Ap4A)-mediated stimulation of glycogen breakdown in isolated rat liver cells. [2-3H]Ap4A showed specific binding to both intact isolated liver cells and plasma membrane fractions prepared from isolated liver cells. HPLC analysis confirmed that binding was mediated by intact Ap4A and not by potential breakdown products (e.g. ATP, adenosine etc). Binding of [2-3H]Ap4A, to isolated liver cell plasma membrane preparations, was successfully displaced by a range of both naturally occurring and synthetic diadenosine polyphosphates with the rank order potency Ap4A ⩾Ap5A > Ap6A > Ap3A > Ap2A. [2-3H]Ap4A binding was not displaced by P1 effectors but was successfully displaced by a range of P2 effectors with the rank order potency 2-methylthio-ATP > ATP > ADP ⩾adenosine 5′-[αβ-methylene]triphosphate > adenosine 5′-[βγ-methylene]triphosphate. These findings are consistent with the interaction of Ap4A with a P2y-like subclass of purinoceptor and are discussed in relation to (1) the known purinoceptor populations in liver cell plasma membranes and (2) observations concerning the binding of diadenosine polyphosphates to purinoceptors in other tissues.

Changes in liver cell plasma membrane polypeptides of phalloidin-treated rats with special reference to the actomyosin complex

1981 ◽  
Vol 59 (3) ◽  
pp. 165-170 ◽  
Author(s):  
B. Tuchweber ◽  
R. J. Vonk ◽  
I. M. Yousef
Keyword(s):  
Liver Cell ◽  
Plasma Membranes ◽  
Contractile Function ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Bile Secretion ◽  
Male Rats ◽  
Bile Canaliculi ◽  
Cell Plasma ◽  
Isolated Liver

Studies on isolated liver cell plasma membranes enriched in bile canaliculi from male rats treated with phalloidin show marked changes in the membrane polypeptides. Upon examination by sodium dodecyl sulfate polyacrylamide gel electrophoresis, a protein component identical in mobility to the myosin standard was dramatically reduced, while that corresponding to actin was increased. It is suggested that a myosin-like protein may be necessary for the contractile function of the actin filaments in the liver cells. The observed modifications may be related to the decreased bile secretion and dilatation of bile canaliculi induced by phalloidin.

Characterization of Rat Liver Cell Plasma Membranes

1975 ◽  
Vol 150 (1) ◽  
pp. 177-184 ◽  
Author(s):  
M. M. Fisher ◽  
D. L. Bloxam ◽  
M. Oda ◽  
M. J. Phillips ◽  
I. M. Yousef
Keyword(s):  
Rat Liver ◽  
Liver Cell ◽  
Plasma Membranes ◽  
Cell Plasma

Titration of Rat Liver with Digitonin: a Well Defined Short Term Damage of Cellular Metabolism

1981 ◽  
Vol 36 (9-10) ◽  
pp. 880-883 ◽  
Author(s):  
Stefan Postius ◽  
Dieter Platt
Keyword(s):  
Lactate Dehydrogenase ◽  
Rat Liver ◽  
Liver Cell ◽  
Plasma Membranes ◽  
Short Term ◽  
Isolated Rat Liver ◽  
Physiological Conditions ◽  
Cell Plasma ◽  
Molecular Compounds ◽  
Isolated Rat

Abstract Carefully performed pulse titration of the isolated rat liver in the course of continuous erythro­ cyte free perfusion with small amounts of digitonin causes a short term perm eability of liver cell plasma membranes with concomitant short lived release of intracellular low or high molecular compounds such as ATP or lactate dehydrogenase. Gluconeogenesis from lactate being completely inhibited during this period restores w ithin about one m inute up to a level that depends on the am ount of perfused digitonin. The described experimental m odel is suggested to be useful for the measurement of cytoplasmic m etabolites under physiological conditions. It moreover offers the possibility to im port foreign substances into liver cells th at normally do not penetrate liver cell plasma membranes.

Liver Cell Plasma Membrane Lipids and the Origin of Biliary Phospholipid

1975 ◽  
Vol 53 (9) ◽  
pp. 989-997 ◽  
Author(s):  
I. M. Yousef ◽  
D. L. Bloxam ◽  
M. J. Phillips ◽  
M. M. Fisher
Keyword(s):  
Plasma Membrane ◽  
Liver Cell ◽  
Membrane Fraction ◽  
Plasma Membranes ◽  
Specific Activity ◽  
Phospholipid Composition ◽  
Bile Canaliculi ◽  
Canalicular Membrane ◽  
Cell Plasma ◽  
Bile Canalicular Membrane

The liver cell plasma membranes of fed male Wistar rats were separated into a fraction rich in bile canaliculi and the remainder of the plasma membrane. Electron-microscopically, the bile canalicular fraction consisted almost exclusively of intact bile canaliculi with their contiguous membranes. The remaining plasma membrane fraction consisted primarily of vesicles and sheets of membranes essentially free from bile canaliculi. The bile canalicular membrane fraction contained relatively more total lipid, cholesterol, and phospholipid, and relatively less protein. Although the phospholipid composition of the two fractions was the same, the specific activity of the bile canalicular membrane phospholipids, up to 12 h following in vivo administration of [2-3H]glycerol, was always significantly greater than that of the remaining plasma membranes, and showed a biphasic response not found in the latter. The specific activity of the phosphatidylcholine, phosphatidylethanolamine and lysophosphatidylcholine of the bile canalicular membranes rose to a peak within 40 min after administration of the label, fell sharply and then rose to a second peak after 120 min. The specific activity of the sphingomyelin and phosphatidylserine plus phosphatidylinositol of the bile canalicular membranes and of all the phospholipids of the remaining plasma membranes did not show the biphasic pattern but increased steadily to reach a maximum at 120 min. The specific activity of biliary phosphatidylcholine followed a pattern identical to that of the phosphatidylcholine, phosphatidylethanolamine and lysophosphatidylcholine of the bile canalicular membrane fraction. These results show that the average rate of turnover of phospholipid in the bile canalicular membranes is considerably greater than that in the remaining plasma membrane and other cell membrane fractions; they indicate that the phospholipid of the bile canalicular membranes exists in two or more pools, turning over at different rates; and they support the concept that biliary phospholipid is derived from the bile canalicular membrane. The results also suggest that bile canalicular phospholipid may be derived from two different sources, in contrast to the remaining plasma membrane.

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