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TABLE 1. CPT-I acrivity in mitochondria isolated fi-orn hepatoma celis
and prhnary hepatocytes
CPT-I activity
(ramal/mira par (nniol/mira par
Celís mg protein) unir GDH activity)
Fao 1.87±0.25 2.56±0.79
HapG2 2.19±0.34 1.87±0.41
Hepatacytas 1.81±0.22 2.34±0.68
Values corresporad to 3 separate experiments. Seo Llie Materials arad Methods for further details.
iradicatirag that CPT-I stimulatiora is mediatad by the inhibitiora of protein phasphatase 1 [9,16].Titis is ira
agraemerar wilih tha obsarvatiara tbat prateira pbosphatase 1 seams to be libe maira phospbatase iravolvad
ira tbe ragularion of libe phospbarylatiora state of libe cytoskoleton, arad ira turra ira libe control ofcytoskeletal
iraliagrity [16]. Ira caratrast ta beparocytes, a sligbt but raot staliisliically sigraificarat stimulatiora of CPT-I lio
okadaic acid was avidenli ira bepalioma celís (Fig. 1). Tbarefora, libe bigh ‘CPT-I activity displayed 1,>’
bepatama celís may be reached by hepatacytas upan challerage lic akadaic acid.
E
a)
o
> D~
tE
E
1---
E
1.2 -
1.0
0.8
0.8
0.4
*
tH’ 0 1 2 3
¡cg [okadaicacíd] (riM)
FIG. 1. Effect of okadaic acid on CPT-I activity in atrached
hepatoma celis and priniary hepatocytes. Feo celis (e),
HepGl celis (o) and primary hepatocytes (‘)were incubated
with varying concentrations of okadaic acid (0, 5, 50, 100and
500 nM) for 45 mm and CPT-I activil>’ was subsequentí>’
determined with the permeabilized-ceII assay. See the
Materisis and Methods for further detalis. Values
correspond tu 4 separate experiments. Significantly different
(P