A histochemical study about the influence of lytic enzymes on plasma membrane enzyme activities in rat liver and kidney

1978 ◽  
Vol 58 (3) ◽  
pp. 177-181 ◽  
Author(s):  
M. J. Hardonk ◽  
T. J. Meskendorp-Haarsma ◽  
J. Koudstaal
Keyword(s):  
Plasma Membrane ◽  
Rat Liver ◽  
Enzyme Activities ◽  
Histochemical Study ◽  
Lytic Enzymes ◽  
Membrane Enzyme ◽  
Liver And Kidney

Liver plasma membrane enzyme activities following glutaraldehyde fixation

Pathology ◽  
1976 ◽  
Vol 8 (1) ◽  
pp. 43-45 ◽  
Author(s):  
P.J. Hertzog ◽  
R.N. Le Page ◽  
P.S. Bhathal
Keyword(s):  
Plasma Membrane ◽  
Enzyme Activities ◽  
Glutaraldehyde Fixation ◽  
Liver Plasma Membrane ◽  
Membrane Enzyme

scholarly journals Specific antibodies and the selective inhibitor ICI 118233 demonstrate that the hormonally stimulated ‘dense-vesicle’ and peripheral-plasma-membrane cyclic AMP phosphodiesterases display distinct tissue distributions in the rat

1987 ◽  
Vol 248 (3) ◽  
pp. 897-901 ◽  
Author(s):  
N J Pyne ◽  
N Anderson ◽  
B E Lavan ◽  
G Milligan ◽  
H G Nimmo ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Plasma Membrane ◽  
Cyclic Amp ◽  
Rat Liver ◽  
White Adipose Tissue ◽  
Tissue Homogenate ◽  
Phosphodiesterase Activity ◽  
Cyclic Amp Phosphodiesterase ◽  
Peripheral Plasma ◽  
Membrane Enzyme

Polyclonal-antibody preparations DV1 and PM1, raised against purified preparations of rat liver insulin-stimulated ‘dense-vesicle’ and peripheral-plasma-membrane cyclic AMP phosphodiesterases, were used to analyse rat liver homogenates by Western-blotting techniques. The antibody DV1 identified only the 63 kDa native subunit of the ‘dense-vesicle’ enzyme, and the antibody PM1 only the 52 kDa subunit of the plasma-membrane enzyme. These antibodies also detected the subunits of these two enzymes in homogenates of kidney, heart and white adipose tissue from rat. Quantitative immunoblotting demonstrated that the amount of these enzymes (by wt.) varied in these different tissues, as did the expression of these two enzymes, relative to each other, by a factor of as much as 7-fold. The ratio of the dense-vesicle enzyme to the peripheral-plasma-membrane enzyme was lowest in liver and kidney and highest in heart and white adipose tissue. ICI 118233 was shown to inhibit selectively the ‘dense-vesicle’ cyclic AMP phosphodiesterase in liver. It did this in a competitive fashion, with a Ki value of 3.5 microM. Inhibition of tissue-homogenate cyclic AMP phosphodiesterase activity by ICI 118233 was used as an index of the contribution to activity by the ‘dense-vesicle’ enzyme. By this method, a tissue distribution of the ‘dense-vesicle’ enzyme was obtained which was similar to that found by using the immunoblotting technique. The differential expression of isoenzymes of cyclic AMP phosphodiesterase activity in various tissues might reflect a functional adaptation, and may provide the basis for the different physiological actions of compounds which act as selective inhibitors.

scholarly journals Hepatic Golgi fractions resolved into membrane and content subfractions.

1982 ◽  
Vol 92 (3) ◽  
pp. 822-832 ◽  
Author(s):  
K E Howell ◽  
G E Palade
Keyword(s):  
Electron Microscopy ◽  
Rat Liver ◽  
Enzyme Activities ◽  
Degree Of Contamination ◽  
Golgi Membranes ◽  
Membrane Enzyme ◽  
Biochemical Assays ◽  
The Reformation ◽  
Liver Homogenates

Golgi fractions isolated from rat liver homogenates have been resolved into membrane and content subfractions by treatment with 100 mM Na2CO3 pH 11.3. This procedure permitted extensive extraction of content proteins and lipoproteins, presumably because it caused an alteration of Golgi membranes that minimized the reformation of closed vesicles. The type and degree of contamination of the fractions was assessed by electron microscopy and biochemical assays. The membrane subfraction retained 15% of content proteins and lipids, and these could not be removed by various washing procedures. The content subfraction was contaminated by both membrane fragments and vesicles and accounted for 5 to 10% of the membrane enzyme activities of the original Golgi fraction. The lipid compositions of the subfractions was determined, and the phospholipids of both membrane and content were found to be uniformly labeled with [33P]phosphate administered in vivo.

Immunologic distribution of an organic anion transport protein in rat liver and kidney

1996 ◽  
Vol 271 (2) ◽  
pp. G231-G238 ◽  
Author(s):  
A. J. Bergwerk ◽  
X. Shi ◽  
A. C. Ford ◽  
N. Kanai ◽  
E. Jacquemin ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Rat Liver ◽  
Organic Anion ◽  
Anion Transport ◽  
Transport Protein ◽  
Membrane Localization ◽  
Organic Anion Transport ◽  
Outer Medulla ◽  
Sds Page ◽  
Liver And Kidney

A Na(+)-independent organic anion transport protein was recently cloned from rat liver using a Xenopus laevis oocyte expression system [E. Jacquemin, B. Hagenbuch, B. Stieger, A.W. Wolkoff, and P.J. Meier, Proc. Natl. Acad. Sci. USA 91: 133-137, 1994]. Although expression of this protein is sufficient for cells to transport the organic anion bromosulfophthalein, little is known about its cell biology or biochemical characteristics. Northern blot analysis performed under high-stringency conditions revealed hybridization with RNA only from liver and kidney; transcripts appeared the same in these two organs. Within kidney, hybridization was greatest when RNA extracted from the outer medulla was used. Immunoblot analysis revealed that in liver, the transporter was enriched in 0.1 M Na2CO3-extracted membranes and sinusoidal plasma membrane preparations, consistent with its being an integral membrane protein. This 80-kDa protein migrated as a 65-kDa protein after treatment with N-glycanase. Immunomorphological examination of liver revealed basolateral plasma membrane localization. In 0.1 M Na2CO3-extracted membranes of kidney, the transporter migrated as an 83-kDa protein on nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). On reduction, it resolved into peptides of 33 and 37 kDa. SDS-PAGE migration of the liver protein was unaffected by reduction. Immunomorphological examination of kidney revealed apical plasma membrane localization in the S3 segment of the proximal tubule of the outer medulla. Differential processing and trafficking of this transporter in liver and kidney may have important functional and regulatory consequences.

Effect of vanadate on rat myometrium plasma membrane enzyme activities

1980 ◽  
Vol 58 (10) ◽  
pp. 1247-1250 ◽  
Author(s):  
A. K. Grover ◽  
T. R. Jones ◽  
E. E. Daniel
Keyword(s):  
Plasma Membrane ◽  
Enzyme Activities ◽  
Contractile Activity ◽  
Membrane Vesicles ◽  
Plasma Membrane Vesicles ◽  
Membrane Enzyme ◽  
Ca Uptake ◽  
Vanadate Inhibition ◽  
Inhibited Acid ◽  
Isolated Rat

Vanadate inhibited K+-activated and K+-activated ouabain-sensitive p-nitrophenyl phosphatases of rat myometrium at nanomolar concentrations. The vanadate concentrations required for 50% inhibition were 220 ± 30 nM for the K+-activated component of this enzyme and 200 ± 30 nM for the K+-activated ouabain-sensitive component. Micromolar concentrations of vanadate inhibited acid and alkaline p-nitrophenyl phosphatases. ATP-dependent Ca uptake by the plasma membrane vesicles was not inhibited by 10 nM – 1 mM vanadate. Mg2+-ATPase was also not affected. Thus K+-activated and K+-activated ouabain-sensitive p-nitrophenyl phosphatase activities of the plasma membrane were most sensitive to inhibition by vanadate. Preliminary experiments demonstrated that similar to ouabain, vanadate inhibited potassium-induced abolition of spontaneous contractile activity of isolated rat myometrium in K-free Krebs. This effect of vanadate is consistent with vanadate inhibition of K+-activated ouabain-sensitive p-nitrophenyl phosphatase.

Sign in / Sign up

Export Citation Format

Share Document