- Type of paper
: Paper in journal
Title: Decreased insulin sensitivity of hepatocytes cultured from
rats on high carbohydrate diet
- Authors:
- Roša, Jagoda (119175)
- Soljačić, Marija (44082)
- Roša, Josip (41562)
Journal: Diabetologia Croatica
Number: 2
ISSN: 0351-0042
Volume: 23
Year: 1994
Pages: from 53 to 58
Number of references: 31
Language: engleski
Summary: Hepatocytes isolated from rats fed a high-protein diet and
cultured 24 hours in a serum-free WO5/BA2000 medium were found to be an
excellent model for testing insulin sensitivity. Insulin (0.08 Šmol/L)
increased the incorporation of C14-glucose (70%) and H3-alanine (100%), and
significantly increased the alpha-amino isobutyric acid (AIB) transport.
Insulin was observed to markedly increase the synthesis (by more than 100%)
and concentration of glycogen. In the same culture conditions, hepatocytes
isolated from high-carbohydrate fed rats were insulin-insensitive, and the
lack of insulin action on the C14-glucose and H3-alanine incorporation into
glycogen was observed. High glycogenolysis was present, both without and
with insulin. The basic AIB transport was also resistant to the biologic
action of insulin. However, in hepatocytes isolated from high-carbohydrate
fed rats , an increased glucose cycling through glycogen and a decreased
hepatic sensitivity to insulin were observed in so differnt metabolic
events as glycogen synthesis and amino acid transport.
Keywords: amino acid transport, diet, glycogen synthesis, glycogenolysis, hepatocytes, insulin, insulin resistance
- Type of paper
: Paper in journal
Title: Effects of fasting on insulin action in primary culture of
rat hepatocytes
- Authors:
- Roša, Jagoda (119175)
- Soljačić, Marija (44082)
- Roša, Josip (41562)
Journal: Diabetologia Croatica
Number: 1
ISSN: 0351-0042
Volume: 24
Year: 1995
Pages: from 25 to 34
Number of references: 65
Language: engleski
Summary: Abnormalities of cellular action during prolonged
starvation were investigated in cultured hepatocytes. Rats from three
experimental groups, including fed controls, and 24-h and 72-h fasted
animals, were used to assess the effects of fasting on insulin sensitivity
in cultured hepatocytes. There was no influence of 24-h (acutaly) fasting
on basal and insulin-stimulated glycogen metabolism and amino-acid
transport. The study demonstrated a defect in hepatocytes from 72-h
(chronically) fasted rats in their ability to accumulate and store
glycogen. Glycogen synthesis did not depend on the concentration of
glucose, gluconeogenic precursors or insulin. In contrast, hepatocytes from
72-h fasted rats appeared much more sensitive to insulin as regarded amino
acid transport.
Keywords: amino acid transport, fasting, glycogen, hepatocytes, insulin, insulin resistance
- Type of paper
: Paper in journal
Title: Insulin sensitivity in hepatocytes cultured from normal
and alloxan/diabetic rats
- Type of paper
: Paper in journal
Title: Insulin sensitiviti in hepatocytes cultured from normal
and alloxan/diabetic rats
- Authors:
- Roša, Jagoda (119175)
- Soljačić, Marija (44082)
- Sljep;evi', Milivoj
- Roša, Josip (41562)
Journal: Diabetologia Croatica
Number: 2
ISSN: 0351-0042
Volume: 23
Year: 1994
Pages: from 139 to 146
Number of references: 53
Language: engleski
Summary: The effects of insulin on hepatic glycogen metabolism and
amino acid uptake were investigated in cultured hepatocytes isolated from
normal as well as from acutely *5 days( and chronically *14 days(
alloxan/diabetic rats.
The results indicated that in hepatocytes from chronically alloxan/diabetic
rats, insulin sensitivity and ability to respond maximally to insulin was
reduced, but in acutely diabetic animals hepatic insulin sensitivity was
enhanced and hepatocytes demostrated the ability to maximally respond to
insulin when compared to insulin action in hepatocyes from normal rats.
These results suggested the observed effects of insulin on glycogen
metabolism and AIB/transport vary depending on the duration and or severity
of the diabetic state.
Keywords: alloxan/diabetes, amino acid transport, dexamethasone, glycogen, hepatocytes, insulin,insulin resistance.
- Type of paper
: Summary in proceedings
Title: Insulin resistance in cultured hepatocytes isolated from
rats on high carbohydrate diet
- Authors:
- Roša, Jagoda (119175)
- Roša, Josip (41562)
Proceedings title: Book of abstracts
Language: engleski
Place: Stockholm, Sweden
Year: 1993
Pages: from 146 to 146
Meeting: 22nd Meeting of the Federation of European Biochemical Societies
Held: from 07/04/93 to 07/09/93
Summary: In hepatocytes from normal rats on high/protein diet and
cultured for 24 h in serum/free WO5BA2000 medium, insulin at concentration
0.08 uM increased glycogen concentration, incorporation of 14C/glucose, 70
%, 3H/alanine 100 %, and significantly increased AIB transport. In
hepatocytes isolated from high/carbohydrate fed rats, 14C/glucose
incorporation into glycogen, direct pathway, was wery high, and insulin did
not significantly change this rate of glucose incorporation. Incorporation
of 3H/alanine, indirect pathway, was wery low and also without any insulin
effect. The lack of insulin action on AIB transport in cells from
high/carbohidrate fed rats was also obserwed. As insulin resistance was
demostraed in so different processes like glycogen synthesis and amino acid
transport, we belive that this cellular insulin resistance resulted from a
defect on the higher level insulin signal transmitting chain.
Other:
- Type of paper
: Summary in proceedings
Title:
- Type of paper
: Summary in proceedings
Title: insulin resistance in normal rat hepatocytes cultured in
high glucose medium
- Authors:
- Roša, Jagoda (119175)
- Soljačić, Marija (44082)
- Roša, Josip (41562)
Proceedings title: Book of abstracts
Language: engleski
Place: Basel, Switzerland
Year: 1995
Pages: from 262 to 262
Meeting: 23rd Meetin of the Federation of European Biochemical Societies, Basel
Held: from 08/13/95 to 08/18/95
Summary: Hyperglikemija effectively induces insulin resistance in
non/insulin dependent diabetes, NIDDM, and in poorly controled
insulin/dependent diabetes mellitus, IDDM. Because glucotoxic effect during
hyperglycemia can be due to the action of the high glucose on insulin
target cells or may induce metabolic events that oppose the effect of
insulin, we sought to determine whether high glucose concentration could
directly cause damage in insulin action at the cellular level. Incubation
of cultured rat hepatocytes in a medium containing high glucose
concentration, 25 mM, did not affect insulin action on amino acid transport
after 24 h, but led to 100 % reduction of insulin effect after 72 h. A
significant decrease in glucose and insulin effectiveness on hepatic
glycogen metabolism was observed after 24 h icubation in high glucose
medium. These results indicate that insulin resistance can occur at the
cellular level as secondary manifestation of hyperglycemia.
- Type of paper
: Summary in proceedings
Title: Mechanism of insulin resistance in rat hepatocytes in
high/glucose medium
- Authors:
- Roša, Jagoda (119175)
- Soljačić, Marija (44082)
- Roša, Josip (41562)
- Editors
- Roša, Jagoda (119175)
- Soljačić, Marija (44082)
- Roša, Jagoda (119175)
Proceedings title: Abstracts book
Language: engleski
Place: Aachen, Germany
Year: 1995
Pages: from 34 to 34
Meeting: Seventh Meeting of the EASD Study Group CONTROL OF METABOLISAM AND INSULIN ACTION
Held: from 10/12/95 to 10/14/95
Summary: It has been reported that high glucose activated protein
kinase C, PKC. The objective of this investigationwas to determine if
phorbol ester or staurosporine ameliorated hepatic insulin resistance.
hepatocytes were incubeted for 72 h in culture medium containing either
low, 5 mM, or high, 25 mM, glucose. High glucose affect the insulin action
on amino acid transport and led to more than 100 % reduction in insulin
effect. After phorbol ester, 0.1 mM, stimulation PKC, there was no
significant change of insulin resistance, however in low glucose medium
there was an enhanced insulin stimulated amino acid transport.
Staurosporine, 1 mM, decreased insulin stimulated amino acid transport in
low glucose medium, but the effect of hyperglycemia on insulin action was
still present. These results indicate that PKC activation is not involved
in high glucose induced insulin resistance on amino acid transport in rat
hepatocytes.
- Type of paper
: Manuscript
Title: Effects of insulin and dexamethasone on glycogen
metabolism and viability of hepatocytes cultured three days in serum-free
medium
- Authors:
- Roša, Jagoda (119175)
- Soljačić, Marija (44082)
- Roša, Josip (41562)
Language: engleski
Summary: In cultures without hormones cell survival during first day
wasalmost 100 % and glycogen content unchanged, but later bothviability as
well as glycogen concentration progressivelydeclined. Insulin was observed
to supress glycogenolysis duringsecond day, but cell viability declined
same as in untreatedcontrols. On the other side cell survival during second
and thirdday was improved by addition dexamethasone, but
glycogenconcentration linearly decreased to a low level. In
culturessupplemented with both insulin and dexamethasone 100 % viabilitywas
observed during all three-day period. In the presence ofdexamethasone,
insulin induced glycogen acumulation and afterthree-day culturing there was
more than 2-fold increase inglycogen concentration.
Keywords: insulin, dexamethasone, glycogen, hepatucyte, viability.
- Type of paper
: Manuscript
Title: Decreased insulin sensitivity in hepatocytes cultured from
the rats on high-carbohydrate diet
- Authors:
- Roša, Jagoda (119175)
- Soljačić, Marija (44082)
- Roša, Josip (41562)
Language: engleski
Summary: Hepatocytes isolated from rats held on high-protein diet
andcultured for 24 h in serum-free WO5/BA2000 medium showed as anexcellent
model for testing insulin sensitivity. Insulin (0.08Šmol/L) increased the
incorporation of 14C-glucose (70 %)3H-alanine (100 %) and significantly
increased alfa-aminoisobutiric acid (AIB) transport, as well as insulin
stronglyincreased glycogen synthesis (over 100 %) and increased
glycogenconcentration. In the same culture condition, hepatocytesisolated
from high-carbohydrate fed rats were insulin insensitiveand the lack of
insulin action on 14C-glucose and 3H-alanineincorporation into glycogen was
observed. High glycogenolysis waspresent, without and with insulin. The
basic AIB transport wasalso resistant to the biologic action of insulin.
However, inhepatocytes isolated from high-carbohydrate fed rats there was
anenhanced glucose cycling throught glycogen and a decrease inheptic
sensitivity to insulin in so different metabolic events asglycogen
synthesis and amino acid transport.
Keywords: amino acid transport, diet, glycogen synthesis, glycogenolysis, hepatocytes, insulin, insulin resistance.
- Type of paper
: Invited lecture
Title: Inzulinsko djelovanje u kulturi hepatocita.
Institution: F.Hofman/La Roche AG
Year: 1993
- Type of paper
: Other
Title: Insulin resistance in cultured hepatocytes isolated from
rats on high-carbohydrate diet
- Authors:
- Roša, Jagoda (119175)
- Roša, Josip (41562)
Type of work: Kongresno saopćenje, 1993, 22nd FEBS Meeting, Stockholm, Sweden.
Language: engleski
Summary: In hepatocytes from normal rats on high-protein diet and
cultured24 h in serum-free WO5/BA2000 medium, insulin (8x10-8
mol/L)increased glycogen concentration, incorporation of 14C-glucose(70 %),
3H-alanine (100 %) and significantly increased AIBtransport. In hepatocytes
isolated from high-carbohydrate-fedrats, 14C-glucose incorporation into
glycogen (direct pathway)was very high and insulin did not significantly
change this rateof glucose incorporation. Incorporation of 3H-alanine
(indirectpathway) was very low and also without any insulin effect. Thelack
of insulin action on AIB transport in cells fromhigh-carbohydrate-fed rats
was also observed. As insulinresistance was demonstrated in so different
processes likeglycogen synthesis and amino acid transport, we believe that
thiscellular insulin resistance resulted from a defect on the higherlevel
insulin signal trasmitting chain.
