CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 9/10, October/November 2013
360
AFRICA
Vitamin E and antioxidant activity; its role in slow
coronary flow
VEYSEL KENAN CELIK, İMGE EZGI EKEN, GÜRSEL YILDIZ, MEHMET BIRHAN YILMAZ, AHMET GURLEK,
HÜSEYIN AYDIN
Abstract
Aim:
Oxidative stress, which is widely recognised as an
important feature of many diseases, can be defined as an
increased formation of reactive oxygen species or decreased
antioxidant defense. In this study we measured plasma vita-
min E levels and total antioxidant activity (AOA) in patients
with slow coronary flow (SCF).
Methods:
The plasma vitamin E levels and AOA were meas-
ured in 40 patients with angiographically diagnosed SCF.
Forty subjects with normal coronary flow (NCF) served as
the control group. SCF and NCF were analysed, and blood
samples were taken for plasma vitamin E levels and AOA.
Plasma vitamin E levels and AOA in patients with SCF were
evaluated and compared to those of patients with NCF.
Results:
There was no significant difference between the two
groups in terms of plasma AOA, lipid profile and C-reactive
protein (CRP) levels but there was a significant difference in
vitamin E levels between the two groups (
p
=
0.001).
Conclusion:
Vitamin E levels were found to be lowered in
patients with SCF compared to the NCF group. The associa-
tion between smoking and vitamin E levels is worth further
investigating in larger samples.
Keywords:
vitamin E, antioxidant activity, slow coronary flow
Submitted 24/5/2013, accepted 25/10/2013
Cardiovasc J Afr
2013;
24
: 360–363
DOI: 10.5830/CVJA-2013-076
The ability of antioxidant defense to scavenge reactive oxygen
species (ROS) is important to protect tissues from oxidative
damage. Cells and biological fluids have an array of protective
antioxidant mechanisms, enzymatic (superoxide dismutase,
catalase, glutathione peroxidase) and non-enzymatic, referred
to as chain-breaking antioxidants (tocopherols, ubiquinol,
carotenoids and flavonoids as lipid phase, and ascorbate,
urate, glutathione and other thiols as aqueous phase), both for
preventing the production of free radicals and for repairing
oxidative damage.
1-4
A free radical contains an unpaired electron in an atomic
orbital. In this state, no molecular species is stable for long.
A free radical will attract other molecules and either give or
receive an electron to make itself thermodynamically stable.
5
The most important free radicals in many disease states are
oxygen derivatives such as hydrogen peroxide, superoxide and
particularly, hydroxyl radical, which is the most harmful for
tissues.
1
Transition metals contain one or more unpaired electrons and
are therefore also radicals when in the elemental state. However,
their key property from the point of view of free radical biology
is their variable valency, which allows them to undergo reactions
involving the transfer of a single electron. The most important
transition metals in human disease are iron and copper.
6
These
elements play a key role in the production of hydroxyl radicals
in vivo
.
7
Hydrogen peroxide and superoxide can be detoxified
enzymatically in the mammalian system by catalase and
superoxide dismutase, respectively. However there is no
enzymatic system that converts or detoxifies hydroxyl radicals.
A hydroxyl radical can be detoxified by non-enzymatic systems.
One of these is the tocopherols (
α
,
β
,
γ
and
δ
), which have a
chromanol ring and a phenyl tail, and differ in the number and
position of the methyl groups on the ring. The most important
lipid-phase antioxidant is probably vitamin E.
8-10
The coronary slow-flow phenomenon was first described
in 1972 by Tambe
et al.
11
The phenomenon is an angiographic
finding characterised by delayed distal vessel opacification in
the absence of significant epicardial coronary disease. However,
since that time, only a limited number of studies have focused on
the aetiology of this unique angiographic phenomenon.
Histopathological studies have revealed the loss of luminary
diameter, and capillary and endothelial damage in these patients.
12
Although the pathophysiological mechanisms of slow coronary
flow phenomenon remain uncertain, there are several hypotheses
that have been suggested, including endothelial activation and
inflammation.
13
However, the phenomenon is not well studied
and deserves further investigation.
In the present study, we investigated plasma vitamin E levels
and antioxidant activity in patients with slow coronary flow
(SCF) and compared them with those with normal coronary
flow (NCF).
Methods
Forty consecutive patients with angiographically diagnosed SCF
in all three epicardial coronary arteries, and 40 subjects with
normal coronary flow as a control group were enrolled in our
study after obtaining informed consent. All patients underwent
selective coronary angiography via the Judkins technique.
Department of Biochemistry, Faculty of Medicine,
Cumhuriyet University, Sivas, Turkey
VEYSEL KENAN CELIK, PhD
İMGE EZGI EKEN, PhD
HÜSEYIN AYDIN, PhD
Clinic of Nephrology, Atatürk State Hospital, Zonguldak,
Turkey
GÜRSEL YILDIZ, MD,
Department of Cardiology, Faculty of Medicine, Cumhuriyet
University, Sivas, Turkey
MEHMET BIRHAN YILMAZ, MD
AHMET GURLEK, MD
