Download Nitric oxide and fibronectin in cardiac tissue of diabetic hypertensive

EL-MINIA MED. BULL. VOL. 19, NO. 2, JUNE, 2008
Ibrahim et al
NITRIC OXIDE AND FIBRONECTIN IN CARDIAC TISSUE OF DIABETIC
HYPERTENSIVE RATS; EFFECT OF CAPTOPRIL
By
Mohamed Abdellah Ibrahim*, Tetsuto Kanzaki**, Adel Hussian Saad***,
Ahmed Mohmed Mahmoud**** and Shiro Ueda*****.
Departments of *Pharmacology, Minia University, Minia City, Egypt.
**Clinical Medicine, Faculty of Pharmacy, Chiba Institute of Science, Shiomi-cho,
Choshi, Chiba, JAPAN, ***Physiology, Minia University, Minia City, Egypt,
****Drug Information and Communication, Graduate School of Pharmaceutical
Sciences, Chiba University, Inohana, Chuo-ku, Chiba City, Japan and
*****Biochemistry, Minia University, Minia City, Egypt.
ABSTRACT:
Diabetes and hypertension are interrelated diseases that represent major risk
factors for developing cardiovascular complications such as cardiomyopathy. The
mechanism of developing diabetic cardiomyopathy is not well documented and may
include modulation of nitric oxide (NO) and extracellular matrix, fibronectin. We
studied effect of experimentally induced diabetes on cardiac NO metabolites (NOx)
and fibronectin in a model of spontaneous hypertensive rats (SHR); and possible
modulation by administration of captopril. Diabetes caused significant decrease in
NOx and increase in fibronectin expression in cardiac tissue of SHR. Four weeks
treatment with captopril prevented cardiac hypertrophy, and decreased fibronectin
expression but not affecting NOx in cardiac tissues of SHR.
KEYWORDS:
Nnitric oxide
Diabetic cardiomyoathy
Fibronectin
Captopril
multifactorial, including modulation of
nitric oxide (NO) and expression of
extracellular
matrix,
fibronectin
(Sowers et al. 1993; Chen et al. 2003).
INTRODUCTION:
Hypertension and diabetes are
interrelated diseases that represent
major risk factors for cardiovascular
diseases (Epstein and Sowers 1992;
Charles and Lee 1995). Both diabetes
and hypertension are associated with
cardiomyopathy
(Grossman
and
Messerli 1996; Sowers and Epstein
2001). Although the clinical and
morphologic features of hypertensivediabetic cardiomyopathy were descrybed more than 2 decades ago (Factor et
al. 1980), the mechanism of developing hypertensive or diabetic cardiomyopathy is not well documented (Lip
et al. 2000). It has been reported that
the mechanisms by which diabetes
produces
cardiomyopathy
are
Nitric
oxide,
which
is
synthesized from L-arginine by nitric
oxide synthase (NOS), plays an
important role in regulating cardiac
functions. Long-term treatment of rats
with the NOS inhibitor NG-nitro-Larginine
methylester
(L-NAME)
results in development of arterial
hypertension, bradycardia and left
ventricular hypertrophy (Johnson and
FRREMAN 1992; Bernatova et al.
1996) decrease of cardiac output
(Hampl et al. 1993), and increased
cardiac fibrosis (Babal et al. 1997;
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EL-MINIA MED. BULL. VOL. 19, NO. 2, JUNE, 2008
Bernatova 1999). The level of NO in
diabetes is somewhat controversial,
with studies providing for an increase
(Graier et al. 1996; Cosentino et al.
1997) a decrease [Balon and Nadler
1997; Pieper GM 1998), or no change
(Smits et al. 1993; Schmetterer et al.
1997).
Fibronectin is an extracellular
matrix
glycoprotein,
and
its
overexpression may contribute to
vascular diseases (Sowers et al. 1993).
It plays a central role in regulating
morphogenesis and functional maturation in developing tissues through its
effects on cell adhesion, differenttiation, and migration (Pichika and
Homandberg, 2004). Both NO and
fibronectin play a role in the development of vascular tissues and the NOS
inhibitor L-NGmonomethylarginine (LNMMA)
decreased
fibronectin
synthesis, whereas the NO donor, Snitroso-N-acetylpenicillamine (SNAP),
increased
fibronectin
synthesis
(Catherine et al. 1999; Pichika and
Homandberg, 2004). Diabetes causes
overproduction of cardiac extracellular
matrix (ECM), which contributes to
diastolic dysfunction (Chen et al.
2000).
Ibrahim et al
strating that ACE-inhibition was
associated with antitrophic effects in
diabetes and hypertension (Lassila et
al. 2003).
Mechanisms that account for
the effects of ACE inhibitors on
diabetes-induced cardiovascular dysfunctions are not clear but may be related
to effects on insulin sensitivity
(Torlone et al. 1993), inhibition of
oxidative stress (Rajagoplan and
Harrison 1996) and/or modulation of
NO pathway (Yayuz et al. 2003).
In the present investigation, we
report the effect of diabetes on cardiac
tissue NO and fibronectin in spontaneous hypertensive rats (SHR) and the
modulation of these effects by the
administration of captopril.
MATERIALS AND METHODS:
Chemicals:
The sources of materials were
as follows: streptozotocin (STZ), and
bovine serum albumin from Sigma
Chemical Co. (St. Louis, MO, USA);
Captopril, Sankyo Co. (Tokyo, Japan);
Nitrite/nitrate colorimetric assay kit
from Caymen Chemical Co. (Ann
Arbor, MI, USA); DC protein assay kit
from Bio Rad Lab (Hercules, CA,
USA); Western blot ECL immunodetection kit from GE healthcare UK
limited (Buckinghamshire, UK).
Currently, one of the most
important therapeutic approaches to
prevent diabetic cardiaovasculr complications is rigorous blood pressure
control (Cooper and Johnston 2000).
Angiotensin converting enzyme (ACE)
inhibitors, because of their protective
effects on the cardiovascular system
and kidney, are regarded as the firstline antihypertensive therapy for
patients with diabetes (World Health
Organization 1999). It has been
reported that reninangiotensin system
may be involved in the pathogenesis of
diabetic
cardiomyopathy,
since
captopril can improve and reverse the
cardiomyopathy of diabetic rats (Rösen
et al. 1995). lassila M, et al. demon-
Antibody:
Antibody against fibronectin
was a generous gift from Dr. Tetsuto
Kanzaki (Kanzaki et al. 1997).
Animal protocol:
Male SHR (Nippon SLC Co.
Ltd. Shizuoka, Japan) aged 10 weeks,
weighing 240-290 g were acclimatized
for one week to handling and blood
pressure measurement by tail-cuff
method. All experimental procedures
were done in accordance with
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EL-MINIA MED. BULL. VOL. 19, NO. 2, JUNE, 2008
institutional ethical guidelines for
animal research (Chiba University).”
Ibrahim et al
reaction using a commercial colorimetric assay kit. Briefly, in the first
step, nitrate was converted to nitrite
utilizing nitrate reductase. In the
second step, the addition of Griess
reagents converted nitrite into a deep
purple azo compound. Photometric
measurements by the microplate reader
(Titertek Multiskan MCC/340, Dainippon seiyaku, Osaka, Japan) at 540 nm
were used to determine the NOx levels.
Induction of diabetes:
Diabetes was induced by a
single intraperitoneal injection of 65
mg/kg STZ (Ibrahim et al. 2005). Rats
with blood glucose ≥ 16.7mmol/L were
considered diabetic and used in the
experiments. The rats were allocated
into 3 groups: control group 1,
(number (n) = 7) non-diabetic SHR
group; group 2, (n = 7) diabetic SHR
group; group 3, (n = 8) diabetic SHR
group receiving captopril for 4 weeks
at 80 mg/kg in drinking water, a dose
previously reported to reduce blood
pressure in both diabetic and nondiabetic SHR (Sharma and Kesavarao
2002).
Immunoblotting of fibronectin in
cardiac homogenates:
The frozen samples were
homogenized in lysis buffer (1% SDS,
300 mM NaCl, 10 mM Tris-HCl, PH
7.4, protease inhibitor Cocktail (Sigma
Co., Japan) 1/100). The homogenates
were centrifuged at 15,000g for 5 min
at 4 C, and the supernatant served as
tissue extracts. Total protein of tissue
extracts was assayed using DC protein
assay kit (Bio RAD Co., Japan). Equal
amounts of tissue proteins were
separated on SDS-PAGE (7.5% polyacrylamide gels) and electrically
transferred to a nitrocellulose membrane (GE healthcare UK Limited).
Western blot analysis was done using
polyclonal antibody against rat fibronectin (a gift from Dr. Kanzaki) after
blocking non-specific binding sites
with 5% bovine serum albumin
(Sigma). For immunodetection, we
used an ECL kit (GE healthcare UK
Limited), according to manufacturer
protocol. Chemiluminescence signals
were quantified using the Las-1000
plus.
Measurement of blood pressure:
Body weight and mean blood
pressure (MBP) were determined once
a week during the course of the
experiment. MBP was measured by the
tail-cuff method in conscious, lightly
restrained rats (Zartz 1990). At least 3
determinations were made at every
session, and the mean of the three
values was used to obtain MBP.
Blood and organ collections:
Rats were anesthetized with
diethyl ether and blood samples were
collected from abdominal aortas.
Plasma samples were stored at –70oC
until assayed.
Determination of cardiac hypertrophy:
The heart was rapidly excised,
dried, weighed and divided by body
weight to determine cardiac index. The
heart was stored at – 70oC for further
assays.
Statistical analysis:
Data were expressed as mean ± SD.
Statistical significance of differences
between groups was evaluated by
using ANOVA, unpaired Student’s t
test and Mann whitney test.
Detection of the level of NO:
Nitrite/nitrate, as marker of NO
level, was determined by Griess
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Ibrahim et al
mm Hg) compared with either group 1
(165 ± 5.85 mm Hg) or group 2 (160 ±
12.5 mm Hg) (Table 1).
RESULTS:
1- Blood glucose, blood pressure, and
cardiac index Blood glucose levels,
four weeks after STZ injection were:
group 1 (8.8±1.0 mmol/L); group 2,
(20.6±5.1 mmol/L); group 3 (26.9±6.9
mmol/L). There was no significant
difference in blood glucose between
groups 2 and 3 (Table 1).
MBP was significantly lower in the
captopril-treated group 3 (120 ± 7.21
Cardiac index (heart weight
(mg)/body weight (g)) was signifycantly lower in the captopril-treated
group 3 (3.4 ± 0.14 mg/g) compared
with either group 1 (3.8 ± 0.15 mg/g)
or group 2 (3.8 ± 0.22 mg/g) (Table 1).
Table 1: Animal conditions and cardiac index
(at 0 week)
Body
Blood
weight
glucose
(g)
(mm/L)
at sacrifice
(4 weeks)
Body
Blood
weight glucose
(g)
(mg/dL)
Mean
Mean
Cardiac
blood
blood
index
pressure
pressure (mg/g)
(mmHg)
(mmHg)
Group1 264
7.2
143
329
8.8
165
3.8
(n = 7)
± 21
± 0.9
± 6.55
± 15
± 1.0
±6
± 0.15
Group2 278
18.1
139
278*
20.6
160
3.8
(n = 7)
±4
± 1.0
± 10.96 ± 23
± 5.1
± 13
± 0.22
Group3 278
19.9
137
258*
26.9
120* ☼ 3.4
(n = 8)
± 13
± 3.6
± 11.66 ± 37
± 6.9
±7
± 0.14*
The results were expressed as means ± S.D., and analyzed by unpaired student t- test.
Values of P < 0.05 were considered statistically significant.
* Significant difference compared with group 1.
☼ Significant difference compared with group 2.
Cardiac NOx level was significantly
decreased in groups 2 and 3 compared
with control group 1. Captopril
treatment did not affect the cardiac
NOx level
2- NO in cardiac tissues
Cardiac NOx levels were 43 ± 18
nmol/mg protein, 22 ± 9 nmol/mg
protein and 24 ± 6 nmol/mg protein in
groups 1, 2 and 3, respectively (Fig. 1).
.
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Ibrahim et al
Fig. 1. Changes of cardiac nitrite and nitrate
NOx in cardiac tiisues
NOx Con. (nmol/mg protein)
70
60
50
40
***
***
30
20
10
0
Group 1
Group 2
Group 3
*** Significant difference compared with group 1
Cardiac nitrite and nitrate were assayed as described in Materials & Methods. Values
are expressed as mean+SD (n=7).
diabetic group compared with control
group 1 (Fig. 2). The band intensities
of group 3 was significantly weaker
than group2, indicating that diabetes
increased fibronectin expression in
aortic tissue of SHR but captopril
administration decreased fibronectin
expression in aortic tissue of diabetic
SHR.
3Immunoblot
analysis
of
fibronectin in aortic tissue
Fibronectin expressions were
examined by immunoblot analysis. The
bands detected by using antibody to
fibronectin, but not by non-immune
serum, were specific to fibronectin
(data not shown). The intensities of
this band were significantly denser in
Fig. 2. Immunoblot analysis of cardiac fibronectin
A)
1
2
3
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Ibrahim et al
Fibronectin in cardiac tissue
B)
Relative fibronectin density
1.6
*
1.4
1.2
**
1
0.8
0.6
0.4
0.2
0
1
2
3
Immunoblot analysis of cardiac fibronectin was performed as described in Materials
and Methods. Fig. 2-A shows the typical band of non-diabetic SHR (1), diabetic SHR
(2) and diabetic SHR receiving captopril (3). Densities of the bands were calculated,
and the relative densities are shown as mean ± SD of four different experiments (Fig.
2-B). *Significant difference compared with group 1. **Significant difference
compared with group 2.
pathway in endothelium (Shen and
Zheng 1999), and a deficiency in
tetrahydrobiopterin (BH4), a cofactor
necessary for NOS activity (Meininger
et al. 2000).
DISCUSSION:
Our findings showed that
diabetes caused a significant decrease
in NO metabolites, nitrite/nitrate
(NOx), in cardiac tissues of SHR
compared with non-diabetic SHR. It
has been reported that diabetes
decreased vascular NO formation,
leading to dysfunction of the vascular
endothelium and contributing to the
development of vascular diseases
(Oyadomari et al. 2001; Shafiei et al.
2003). Ibrahim, et al., reported that
NOS-3 expression and NOx decreased
in rat aorta after STZ injection
(Ibrahim et al. 2005). The reduction in
NO availability in diabetes has been
attributed to either enhanced degradation of nitric oxide by excessive
production of superoxide anion (Hink
et al. 2001), or impairment of NO
formation due to several factors
including a defect in substrate supply
for NO synthesis such as a defect in the
utilization of L-arginine by NOS
(Pieper and Dondlinger 1997),
impaired capacitative Ca2+ entry
The molecular mechanism of
endothelial NO regulation in diabetes
is complex and not fully understood,
but the following mechanisms have
been suggested (Artwohl et al. 2003).
First, hyperglycemia can markedly
activate the beta II isoform of protein
kinase (PKC) in endothelial cells by
promoting de novo synthesis of
diacylglycerol (DAG) and increasing
mitochondrial superoxide production.
Then, activated PKC can suppress
NOS-3 transcription. Second, hyperglycemia, by increasing free radical
production, can lead to a decrease in
NO synthesis and/or availability.
Third, chronic hyperglycemia increases
aldose reductase activity, leading to an
increase in glucose metabolism
through the polyol pathway that
consumes NADPH. Because NADPH
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EL-MINIA MED. BULL. VOL. 19, NO. 2, JUNE, 2008
is also an essential cofactor for NOS in
the synthesis of NO, its depletion as a
result of hyperglycemia could lead to a
reduction in NO production. Fourth,
accumulation of advanced glycation
end products as a result of sustained
high plasma glucose concentrations has
been shown to reduce NO production
by directly reacting with NO or
triggering apoptosis in vascular
endothelial cells. In addition, the lack
of insulin in diabetes may contribute to
the effect of decreased NOS-3, because
physiological concentrations of insulin
can increase NOS-3 gene expression,
protein and activity (Kuboki et al.
2000).
Ibrahim et al
finding is consistent with previous
reports. (Lindsay et al. 1997; Vural et
al. 2002).
Captopril
reduced
blood
pressure without affecting NOx
concentrations in cardiac tissue of
diabetic SHR. In support of this
finding, Bernatova et al. reported that
captopril prevented hypertension and
left ventricular hypertrophy without
affecting NOS activity in rats
(Bernatova et al. 1996). Similarily,
Kawabata et al. reported that protection
of the myocardium against ischemia
reperfusion injury with ACE inhibitor,
temocaprilat, was not abolished by
nitric oxide synthase inhibitor in rabbit
hearts (Kawabata et al. 2001).
Trauernich et al. reported that enalapril
prevented cerebrovascular dysfunction
in diabetic rats without altering the
expression of NOS-3 protein in
cerebral microvessels (Trauernich et al.
2003). In contrast, other studies
reported the enhanced effect of ACE
inhibitors on NOS expression and
activity (Linz et al., 1997; Bosc et al.
2000). Although the reason for these
conflicting data is unclear, differences
in the duration of drug administration
and/or doses administered might
provide some explanations. Indeed, it
has been reported that administration
of ACE inhibitors, captopril or
enalapril for 1 or 3 months respecttively, did not improve NO production
or NOS expression (Bernatova et al.
1996; Trauernich et al. 2003). While
treatment with the ACE inhibitors,
enalapril or ramipril for 6 months or 2
years,
respectively,
induced
a
significant increase in NOS activity
and expression [(Linz et al., 1997;
Bosc et al. 2000). Scribner et al.
reported that captopril at only high
concentrations
(above
30
μM)
increased NO synthesis in aortic
endothelial cells as evidenced by the
However, there is no clear
consensus regarding NO production
and the relation between NO production and cardiaovascular dysfunction
in diabetes (Pieper 1999).
This
diversity of opinion is probably based
on differences in the type of the vessel
examined, duration of diabetes, degree
of hyperglycemia, insulin concentration, presence or absence of diabetic
complications, and the experimental
model (Pieper 1999). StockklauserFarber et al. reported that the
myocardial NOS activity of diabetic
rats reached 2.5 times as high as
controls after 4 weeks of diabetes,
declined to the control level after 15
weeks, and decreased to lower than
control after 46 weeks (StockklauserFarber et al. 2000).
Diabetic SHR treated with
captopril for 4 weeks showed a
significant reduction in MBP. The
blood pressure-lowering effect of
captopril has been well documented
(Silberbauer et al. 1982). The MBP
values of diabetic rats were similar to
those of non-diabetic rats, indicating
that STZ-induced diabetes had no
significant effect on blood pressure
during the period of this study. This
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increased production of cyclic GMP
(Scribner et al. 2003).
Ibrahim et al
decrease in NOx in cardiac tissue, our
findings raise a question about the
possible link between NO and
fibrenectin in diabetic cardimyopathy.
It has been reported that Both NO and
fibronectin play a role in the
development of vascular tissues and
the NOS inhibitor L-NMMA decreased
fibronectin synthesis, whereas the NO
donor, SNAP, increased fibronectin
synthesis (Catherine et al.1999;
Pichika and Homandberg, 2004).
Further investigation is needed to
confirm such a relation.
Our results showed that
diabetes
significantly
increased
fibronectin expression in hearts of
SHR. Although, the pathogenesis of
diabetic cardiovascular disease is
multifactorial, excessive accumulation
of ECM is one of the main
pathological hallmarks (Evans et al.
2000). It has been reported that
hyperglycemia increased fibronectin
protein and mRNA expression in
embryonic hearts (Smoak 2004). A
study by Argano M et al. reported that
diabetic
cardiomyopathy
is
characterized by myocyte loss and
showed that oxidative stress, induced
by hyperglycemia, caused myocardial
fibrosis and impaired contractile
function in the left ventricle of diabetic
rats (Aragno et al. 2008).
In summary, diabetes decreased
NO level and increased fibronectin
expression in hearts of SHR rats. Antihypertensive and anti-hypertrophic
effects of captopril are associated with
decrease in fibronectin expression in
cardiac tissue without significant
changes in cardiac NO.
Administration of captopril in
diabetic SHR prevented cardiac
hypertrophy and decreased fibronectin
expression in cardiac tissue compared
with non-treated rats. It has been
reported that captopril, prevented
cardiomyopathy
in
experimental
chronic aortic valve regurgitation and
these effects might be related to
decrease of fibronectin expression in
left ventricles (Plante et al. 2004).
REFERENCES:
1. Aragno M, Mastrocola R,
Alloatti G, Vercellinatto I , Bardini P,
Geuna S, Catalano MG, Danni O,
Boccuzzi G (2008) Oxidative stress
triggers cardiac fibrosis in the heart of
diabetic rats.Endocrinology 149:380-8.
2. Artwohl M, Graier WF, Roden
M (2003) Diabetic LDL triggers
apoptosis in vascular endothelial cells.
Diabetes 52: 1240-1247.
3. Babal P, Pechanova O, I.
Bernatova I, S. Stvrtina S (1997)
Chronic inhibition of NO synthesis
produceds myocardial fibrosis and
arterial media hyperplasia. Histol
Histopathol 12: 623-629.
4. Balon TW, Nadler JL (1997)
Evidence that nitric oxide increases
glucose transport in skeletal muscle. J
App Physiol 82: 359-63.
5. Bernatova I, Pechanova O,
Kristek F (1999) Mechanism of
structural remodeling of the rat aorta
during long-term L-NAME treatment.
Jpn J Pharmacol 81: 99-106.
Recently, Zhang X et al.
showed that AT (1) receptor antagonist
involved in the pathology of
myocardial
remodeling
and
development of congestive heart
failure by the increasing expressions of
metalloproteinases which contribute to
degradative
extracellular
matrix
fibronectin in myocardium (Zhang et
al. 2006).
Although, it was not the aim of
our study to explore a relation between
increased expression of fibronectin and
335
EL-MINIA MED. BULL. VOL. 19, NO. 2, JUNE, 2008
6. Bernatova I, Pechanova O,
Simko F (1996) Captopril prevents
NO-deficient hypertension and left
ventricular
hypertrophy
without
affecting nitric oxide synthase activity
in rats. Physiol Res 45: 311-316.
7. Bernatova I. Pechanova O,
Simko F (1996) Captopril prevents
NO-deficient hypertension and left
ventricular
hypertrophy
without
affecting nitric oxide synthase activity
in rats. Physiol Res. 45: 311-316.
8. Bosc LB, Kurnjek ML, Muller
A, Basso N (2000) Effect of chronic
angiotensin II inhibition on the
cardiovascular system of the normal
rat. Am J Hypertens 13: 1301-1307.
9. Catherine A, Mason E, Chang
P, Fallery C, Rabinovitch M (1999)
Nitric oxide mediates LC-3-dependent
regulation of fibronectin in ductus
arteriosus intimal cushion formation.
FASEB J. 13, 1423–1434 (1999)
10. Charles CM, lee DA (1995)
prevention and treatment of the
complications of diabetes mellitus. N.
Eng. J. Med. 332: 1210-1217.
11. Chen S, Evans T, Mukherjee K,
Karmazyn M, Chakrabarti S (2000)
Diabetes induced myocardial structural
changes: role of endothelin-1 and its
receptors. J Mol Cell Cardiol 32:1621–
1629.
12. Chen S, Khan ZA, Cukiernik
M, Chakrabarti S (2003) Differential
activation of NF-kappa B and AP-1 in
increased fibronectin synthesis in
target organs of diabetic complications.
Am J Physiol Endocrinol Metab 284:
E1089–E1097.
13. Cooper ME, Johnston CI
(2000) Optimizing treatment of
hypertension in patients with diabetes.
JAMA 283: 3177-3179.
14. Cosentino F, Hishikawa K,
Katusic ZS, Luscher TF (1997) High
glucose increase nitric oxide synthase
expression and superoxide anion
generation in human aortic endothelial
cells. Circulation 96: 25-8.
Ibrahim et al
15. Epstein M, Sowers JR (1992)
Diabetes mellitus and hypertension.
Hypertension 19: 403-418.
16. Evans T, Mukherjee K,
Karmazyn M, Chakrabarti S (2000)
Diabetes induced myocardial structural
changes: role of endothelin-1 and its
receptors.
J Mol Cell Cardiol
32:1621–1629.
17. Factor
SM,
Minase
T,
Sonnenblick EH (1980) Clinical and
morphological features of human
hypertensive-diabetic cardiomyopathy.
Am Heart J 99: 446–458.
18. Graier WF, Simecek S,
Kukovetz WR, Kostner GM (1996)
High D-glucose-induced changes in
endothelial Ca +2/EDRF signaling are
due to generation of superoxide anions.
Diabetes 45:1386-95.
19. Grossman E, Messerli FH
(1996) Diabetic and hypertensive heart
disease. Ann Intern Med 125: 304–
310.
20. Hampl V, Archer SI, Nelson
DP, Weir EK (1993) Chronic EDRE
inhibition and hypoxia: effects on
pulmonary circulating and systemic
blood pressure. J Appl Physiol 75:
1748-1757.
21. Hink U, Li H, Mallnau H
(2001)
Mechanisms
underlying
endothelial dysfunction in diabetes
mellitus. Circ Res. 88: e14-e22.
22. Ibrahim MA, Kanzaki T,
Yamagata S, Sattoh N, Ueda S (2005)
Effect of diabetes on aortic nitric oxide
in spontaneously hypertensive rats;
Does captopril modulate this effect?.
Life Science 77: 1003-1014.
23. Johnson RA, FRREMAN RH
(1992) Sustained hypertension in rat
induced by blockade of nitric oxide
production. Am J Hypertens. 5: 919922.
24. Kanzaki T, Shiina T, Saito Y,
Zardi L, Morisaki N (1997):
Transforming growth factor-β receptor
and fibronectin expressions in aortic
336
EL-MINIA MED. BULL. VOL. 19, NO. 2, JUNE, 2008
smooth muscle cells in diabetic rats.
Diabetologia 40: 383-391.
25. Kawabata H, Ryomoto T,
Ishikawa K (2001) Cardioprotection
with angiotensin converting enzyme
inhibitor and angiotensin II type 1
receptor antagonist is not abolished by
nitric oxide synthase inhibitor in
ischemia-reperfused rabbit hearts.
Hypertens Res 24: 403-409.
26. Kuboki K, Jiang ZY, Takahara
N (2000) Regulation of endothelial
constitutive nitric oxide synthase gene
expression in endothelial cells and in
vivo: a specific vascular action of
insulin. Circulation 101: 676-681.
27. Lassila M, Davis BJ, Allen TJ,
Burrell LM, Cooper ME, Cao Z (2003)
Cardiovascular hypertrophy in diabetic
spontaneously
hypertensive
rats:
optimizing blockade of the reninangiotensin system. Clin Sci (Lond)
104 (4): 341-7.
28. Lindsay RM, Peet RS, Wikie
GS (1997) In vivo and in vitro
evidence of altered nitric oxide
metabolism in the spontaneously
diabetic, insulin-dependent BB/ Edinburgh rat. Br J Pharmacol 120:1-6.
29. Linz W, Jessen T, Becker R,
Scholkens B, Wiemer G (1997) Longterm ACE inhibition doubles lifespan
of hypertensive rats. Circulation 96:
3164-3162.
30. Lip GY, Felmeden DC, LiSaw-Hee FL (2000) Hypertensive heart
disease: a complex syndrome or a
hypertensive “cardiomyopathy”? Eur
Heart J 21: 1653–1665.
31. Meininger CJ, Marinos RS,
Hatakeyama K (2000) Impaired nitric
oxide
production
in
coronary
endothelial cells of the spontaneously
diabetic BB rat is due to tetrahydrobiopterin deficiency. Biochem J 349:
353-356.
32. Oyadomari S, Gotoh T, Aoyagi
K, Araki E, Shichiri M, Mori M (2001)
Coinduction of endothelial nitric oxide
synthase and arginine recycling
Ibrahim et al
enzymes in aorta of diabetic rats. Nitric
Oxide: Biology and Biochemistry 5:
252-260.
33. Pichika R and Homandberg G
(2004) Fibronectin fragments elevate
nitric oxide (NO) and inducible NO
synthetase (iNOS) levels in bovine
cartilage and iNOS inhibitors block
fibronectin fragment mediated damage
and promote repair. Inflammation
Research 53: 405-412.
34. Pieper GM (1998): Review of
alterations in endothelial nitric oxide
production in diabetes. Hypertension
31:1047-60.
35. Pieper GM (1999) Enhanced,
unaltered and impaired nitric oxidemediated endothelium-dependent relaxation in experimental diabetes
mellitus: importance of disease
duration. Diabetologia 42: 204-103.
36. Pieper GM, Dondlinger LA
(1997) Plasma and tissue arginine are
decreased in diabetes: acute arginine
supplementation restores endotheliumdependent relaxation by augmenting
cGMP production. J Pharmacol Exp
Ther 283: 684-681.
37. Plante E, Gaudreau M,
Lachance D, Drolet MC, Roussel
Gauthier C, E. Lapointe E, Arsenault
M, Couet J (2004) Angiotensinconverting enzyme inhibitor captopril
prevents volume overload cardiomyopathy in experimental chronic aortic
valve regurgitation. Can J Physiol
Pharmacol. 82: 191-9.
38. Rajagoplan S, Harrison DG
(1996) Reversing endothelial dysfunction with ACE inhibitors: a new trend.
Circulation 94: 240-243.
39. Rösen R, Rump AF, Rösen P
(1995) The ACE-inhibitor captopril
improves myocardial perfusion in
spontaneously diabetic (BB) rats.
Diabetologia 35(5): 509-17.
40. Schmetterer L, Findl O,
Fasching P, Ferber W, Strenn K,
Breiteneder H (1997) Nitric oxide and
337
EL-MINIA MED. BULL. VOL. 19, NO. 2, JUNE, 2008
ocular blood flow in patients with
IDDM, Diabetes 47: 653-659.
41. Scribner AW, Loscalzo J,
Napoli C (2003) The effect of
angiotensin-converting enzyme inhibition on endothelial function and
oxidant stress. Eur J Pharmacol 482:
95-99.
42. Shafiei M, Nobakht M, Fattahi
M, Kohneh-Shahri L, Mahmoudian M
(2003) Histochemical assessment of
nitric oxide synthase activity in aortic
endothelial cells of streptozotocininduced diabetic rats. Pharmacology
10: 63-67.
43. Sharma JN, Kesavarao U
(2002) Effect of captopril on urinary
kallikrein,
blood
pressure
and
myocardial hypertrophy in diabetic
spontaneously
hypertensive
rats.
Pharmacology 64: 196-200.
44. Shen JZ, Zheng XF (1999)
Characteristics of impaired endothelium-dependant relaxation of rat
aorta after streptozotocin-induced
diabetes. Zhongguo Yao Li Xue Bao
20: 844-850.
45. Silberbauer K, Stanek B,
Temple H (1982) Acute hypotensive
effect of captopril in man modified by
prostaglandin synthesis inhibition. Br J
Clin Pharmacol 14: 87S-93S.
46. Smits P, Hersbach FM, Jansen
A, Thien T, Lutterman JA (1993)
Impaired vasodilator response to atrial
natriuretic factor in IDDM. Diabetes
42: 1454-61.
47. Smoak
IW
(2004)
Hyperglycemia-induced TGFbeta and
fibronectin expression in embryonic
mouse heart, Dev Dyn. 231: 179-89.
48. Sowers JR, Epstein M, Frohlich
ED (2001) Diabetes, hypertension, and
cardiovascular disease: an update.
Hypertension 37: 1053–1059.
49. Sowers JR, Standley PR,
RamJL, Jacober S (1993) Hyperinsulinemia, insulin resistance, and
hyperglycemia: contributing factors in
the pathogenesis of hypertension and
Ibrahim et al
atherosclerosis. Am J Hypertens. 6:
260S-270S.
50. Stockklauser-Farber
K,
Ballhausen T, Laufer A, Rosen P
(2000) Influence of diabetes on cardiac
nitric oxide synthase expression and
activity. Biochim Biophys Acta 1535:
10-20.
51. Torlone E, Britta M, Rambotti
AM (1993) Improved insulin action
and glycemic control after long-term
angiotensin-converting
enzyme
inhibition in subjects with arterial
hypertension and type II diabetes.
Diabetes Care 16: 1347-1355.
52. Trauernich AK, Sung H, Patel
KP, Mayhan WG (2003) Enalapril
prevents
impaired
nitric
oxide
synthase-dependent
dilatation
of
cerebral arterioles in diabetic rats.
Stroke 34: 2698-2703.
53. Vural P, Cevik A, Curgunlu A,
Canbaz M (2002) Effects of diabetes
mellitus and acute hypertension on
plasma nitric oxide and endothelin
concentrations in rats. Clinica Chimica
Acta 320: 43-47.
54. World Health Organization
(1999) World Health Organization
international society of hypertension
guidelines for the management of
hypertension. J Hypertens 17: 151-183.
55. Yayuz D, Kucukkaya B, Haklar
G, Ersoz O, Akoglu E, Akalin S (2003)
Effects of captopril and losartan on
lipid peroxidation, protein oxidation
and nitric oxide release in diabetic rat
kidney, Prostaglandins, Leukotrienes
and Essential Fatty Acids 69: 223-227.
56. Zartz R (1990) A low cost tailcuff method for the estimation of mean
arterial pressure in conscious rats. Lab
Anim Sci 40: 198-201.
57. Zhang X, Yang YJ, Zhu WL,
Huang Y, Z. Zhu ZM (2006) Effects of
angiotensin II receptor antagonism on
matrix
metalloproteinases
and
fibronectin in rats with experimental
myocardial infarction. Zhonghua Xin
Xue Guan Bing Za Zhi 34: 029-34.
338
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‫مستوي اكسيد النيتريك والفيبرونيكتين في نسيج عضلة القلب في الجرزان‬
‫المصابة بمرض السكر المصاحب لضغط الدم المرتفع‪ .‬تأثير عقار الكابتوبريل‬
‫ً‬
‫إن مرض البول السكري وارتفاع ضغط الدم من االمراض المتداخلة والتي تمثل واحدة‬
‫من أخطر العوامل المؤدية الي مشكالت وأمراض القلب والشرايين مثل ضعف عضلة القلب‪.‬‬
‫ان ألية حدوث ضعف عضلة القلب في حاالت مرض البول السكري غير مؤكدة حتي االن‬
‫والتي قد تشمل بعض التعديل في مستوي اكسيد النيتريك و القلب الخلوى الخارجى‬
‫والفيبرونيكتين‪ .‬قد تم دراسة بدراسة تأثير مرض البول السكري علي مستوى اكسيد النيتريك‬
‫والفيبرونيكتين في عضلة القلب في نموذج الجرزان ذات ضغط الدم المرتفع التلقائي وكذلك‬
‫احتمالية تعديلها باستخدام عقار الكابتوبرل‪ .‬لقد أثبتت الدراسة أن مرض السكر سبب نقص ذات‬
‫داللة احصائية ملحوظة في مستوي اكسيد النيتريك ومعدل افراز الفيبرونيكتين في عضلة القلب‬
‫للجرذان المرتفعة ضغط الدم التلقائي مقارنة بالمجموعة الضابطة‪ .‬كما أن أربعة أسابيع من‬
‫العالج بواسطة الكابتوبرل خفضت ضغط الدم ومنعت تضخم عضلة القلب وقللت من معدل‬
‫افراز الفيبرونيكتين ولكنها لم تكن ذا تأثير ملحوظ علي مستوي اكسيد النيتريك‪.‬‬
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