Fractionation of isolated liver cells after disruption with a nitrogen bomb and sonication

1982 ◽  
Vol 57 (1) ◽  
pp. 1-13
Author(s):  
F. Autuori ◽  
U. Brunk ◽  
E. Peterson ◽  
G. Dallner

Hepatocytes from rat liver were prepared by perfusion with collagenase, and rough and smooth microsomes and mitochondria were prepared after cell disruption. By applying 1000 lb/in2 (1 lb/in2 = 6.9 kPa) in a nitrogen bomb followed by decompression, 75% of the cells were disrupted after four consecutive treatments. Intact mitochondria, and rough and smooth microsomes with little contamination were prepared from the homogenate. A more rapid disruption was attained by a short sonication with a low output, thus increasing the efficiency of homogenization. The microsomal subfractions prepared from this homogenate were comparable to those obtained after decompression. Sonication resulted in smooth microsomes, which exhibited a higher contamination with non-microsomal membranes. These, however, were partly removed by additional centrifugation with a discontinuous sucrose gradient containing divalent cations.

1980 ◽  
Vol 186 (1) ◽  
pp. 35-45 ◽  
Author(s):  
A J Dickson ◽  
C I Pogson

Methods have been derived which permit the isolation of undergraded polyribosomes from isolated rat liver cells. Under the conditions used the polyribosome profile of hepatocytes immediately after isolation was essentially identical with that from intact liver. However, during incubation of cells in complex physiological media there was a progressive dissociation of polyribosomes. The addition of a variety of factors that produce reaggregation of polyribosomes in rat liver in vivo did not prevent dissociation during cell incubations. Although large polyribosomes were lost most rapidly, the albumin-synthesizing capacity of isolated cells was not selectively lost when compared with total protein synthesis. The significance of these results for the use of isolated hepatocytes in the study of liver protein synthesis is discussed.


1996 ◽  
Vol 314 (2) ◽  
pp. 687-693 ◽  
Author(s):  
Mandy EDGECOMBE ◽  
Alexander G. McLENNAN ◽  
Michael J. FISHER

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.


1986 ◽  
Vol 240 (1) ◽  
pp. 259-263 ◽  
Author(s):  
M Salter ◽  
C I Pogson

At saturating concentrations of tryptophan, the activity of tryptophan 2,3-dioxygenase was the same in isolated liver cells and in extracts with added haematin. Intraperitoneal injection of haematin did not increase tryptophan oxidation in livers subsequently perfused in situ. Preincubation of liver cells with physiological concentrations of tryptophan caused maximal saturation of tryptophan 2,3-dioxygenase with haem in liver cells. In cell-free extracts tryptophan 2,3-dioxygenase exhibited complex kinetics with haem. The results have important implications for the understanding of the role of haem in tryptophan metabolism.


FEBS Letters ◽  
1981 ◽  
Vol 133 (2) ◽  
pp. 201-204 ◽  
Author(s):  
B.O. Christophersen ◽  
Jon Norseth

1983 ◽  
Vol 32 (1) ◽  
pp. 13-26 ◽  
Author(s):  
Bernard Portha ◽  
Hilda Chamras ◽  
Yvonne Broer ◽  
Luc Picon ◽  
Gabriel Rosselin

1960 ◽  
Vol 235 (5) ◽  
pp. 1354-1358
Author(s):  
Robert L. McGeachin ◽  
Betty Ann Potter

Sign in / Sign up

Export Citation Format

Share Document