Abstracts
of World Literature
Insulin-like growth factor binding
proteins in arterial
hypertension: relationship to
left Ventricular
hypertrophy.
Diez J; Laviades C; Martinez E; Gil MJ; Monreal I;
Fernandez J; Prieto J
Department of Internal Medicine' University of
Navarra' Pamplona' Spain.
OBJECTIVE:
it was reported previously that circulating insulin-like
growth factor I levels are abnormally elevated in patients
with essential hypertension and left ventricular hypertrophy.
Tissue availability of the factor depends on the distribution
of the circulating hound factor between its high-and
low molecular mass binding proteins' only the latter
being able to cross the endothelium. The aim of this
study was to investigate whether the presence of the
different serum binding proteins is altered in-patients
with essential hypertension and left ventricular hypertrophy.
DESIGN:
The study was performed in 30 never-treated patients
with essential hypertension and 30 age and sex-matched
normotensive subjects. Patients were separated into
two groups according to the presence or the absence
of echocardiographically determined left ventricular
hypertrophy.
METHODS:
Plasma insulin-like growth factor I levels was determined
by specific radioimmunoassay. The different molecular
forms of its serum binding proteins were analyzed by
Western blotting using [l25I -labeled insulin-like growth
factor]. A densitometric scanning of the blots was performed
to analyze the quantitative relationships between the
different forms of binding proteins.
RESULTS:
Insulin-like growth factors I level were significantly
higher in the hypertensive patients with than in the
hypertensive patients without left ventricular hypertrophy
or in the normotensive subjects. Compared with the normotensive
subjects' both hypertensive patients subgroups exhibited
increased high-molecular mass binding protein type 3
and decreased low-molecular mass binding proteins types
1 and 2. However' changes in the binding proteins were
more marked in the hypertensive patients without than
in the hypertensive pwith left ventricular hypertrophy.
Accordingly' the ratio of low- to high-molecular mass
binding proteins (an index of insulin-like growth factor
I bioavailability) was higher in the hypertensive patients
with than in the hypertensive patients without left
ventricular hypertrophy.
CONCLUSIONS:
These results show that the distribution of the
molecular forms of serum insulin-like growth factor
binding proteins is altered in patients with essential
hypertension' independently of insulin-like growth factor
1 levels This suggests that regulation of the binding
proteins is abnormal in essential hypertension. Whether
the tissue availability of circulating insulin-like
growth factor I is higher in hypertensive patients with
than in hypertensive patients without left ventricular
hypertrophy merits further investigation.
J
Hypertens, 13:349-55, 1995 Mar
Factors
influencing LVM in hypertensive type-I
diabetic patients.
Gerdts E; Myking OL; Lund-Johansen P; Omvik P
Department of Heart Disease' Haukeland Hospital'
Bergen' Norway.
Diabetes
mellitus is associated with a high prevalence of hypertension
and left ventricular hypertrophy (LVH)' and a causative
relationship with abnormal sodium metabolism in diabetic
patients has been suggested. Factors influencing left
ventricular mass (LVM) were assessed in 30 hypertensive
type- 1 diabetic patients' mean age 46 +/- 9 (range
24-67) years with a mean duration of diabetes and hypertension
of 19 +/- 10 and 6 +/- 5 years' respectively. In the
total study population' casual blood pressure was 163/94
+/- 24/10 mmHg and 24 h blood pressure was 155187 +/-17/8
mmHg. Twenty-four-hour urine samples were obtained to
measure daily albumin excretion (0.77 +/- 1.06 g) and
dietary sodium intake was assessed as 24 h sodium excretion
(173 +/-77 rnmol). Creatinine clearance averaged 1.41
+/- 0.53 ml/s. LVM determined by echocardiography was
221 +/- 74 g (range 104-408 g) and 33% of the patients
had LVH. Multiple regression analysis identified dietary
sodium intake and plasma atrial natriuretic peptide
as independent predictors of LVM (R2 = 0.52' p <0.00l).
No significant association was found between LVM and
blood pressure or albuminuria. The results propose dietary
sodium intake as an important factor in the development
of LVH in hypertensive type-I diabetic patients.
Blood
Press, 6:197-202, 1997 Jul
Abstracts
of Local Literature
Plasma level of endothelin 1, insulin
and catecholamines are
not increased in patients with essential HTN and no target
organ damage
Insulin
resistance and reactive hyperinsulinaemia commonly occur
in-patients with essential hypertension (EHT). However,
the link between vascular and metabolic disturbances
is still unclear. Endothelin l(ET- 1) is a very potent
vasoconstrictor peptide whose role in hypertension is
still controversial. Recently, the possibility that
hyperinsulinaemia may potentiate ET- 1 gene expressiona
nd its receptor mediated action amy be relevant to the
role of hyperinsulinaemia in the pathogenesis of cardiovascular
diseases. Multiple experimental evidences point to an
interaction between ET- 1 and catecholamines (catechols)
suggesting that sympathetic activity may be modulated
by ET- 1. The aim of the work was to study the plasma
levels of these hormones in mild versus severe hypertensive
pts and the relation of these hormones to BP levels
in these patients.
Forty
patients with EHT and no target organ damage were studied.
They were not diabetic, not obese and not on antihypertensive
treatment for the last 2 weeks. They were assigned to
either of 2 groups according to blood pressure (BP)
level: Gr A included 20 pts with mild EHT (BP> 14(3)190
and < 160/100). mean age was 52+8 years. Grp B included
20 patients with severe EHT (BP> 1801110). mean age
was 52.8 + 9 years. Twenty normotensive volunteers served
as controls (C). mean age was 49.6 years. Plasma levels
of ET--1 and insulin were measured by specific radioimmuno
assay and catechols by high performance liquid chromatography.
Molar insulin/glucose ratio (I/G) was calculated in
the fasting state and 1h and 2h after an oral glucose
load of 75 gm
Results:
| |
C |
Gr
A |
Gr
B |
| F.ET-l
(pg/ml) |
0.36
+
0.19 |
0.5
+
0.23 |
0.39
+
0.17 |
| F.Catechols
(nmol/ml) |
2.23
+
1.03 |
3.68
+
2.47 |
3.4
+
2.69 |
| F.Insulin
(u/ml) |
8.9
+
2.4 |
8.7
+
2.3 |
9
+
1.8 |
| I/G
-2h |
44.2
+
24.7 |
32.6
+
18.7 |
56.4
+
41.3
* |
P
< 0.05 Vs Gr A
No
significant difference was found between the 3 groups
as regards the plasma levels of these hormones. It was
only the I/C ratio 2 hours after an oral glucose load
which differed significantly between Gr B and Cr A..
No significant correlation was found between plasma
levels of studied hormones and systolic, diastolic and
mean BP in the same patients.
In
conclusion, plasma levels of ET- I, catechols and insulin
are not related to B levelsin pts with EHT and no target
organ damage. Severe hypertension is associated with
increasing insulin resistance, which is also unrelated
to BP level. The fact that ET-l is mainly an autocrine/paracrine
hormone and its circulating level does not reflect the
local concentration of the peptide in the vessel wall
may explain the lack of correlation between plasma levels
of studied hormones as well as the lack of their correlation
with the magnitude of BP.
Abstract
presented in the 2nd meeting of the Egyptian
Hypertension Society 1996.
Extent
and functional capacity of coronary collateral
circulation in hypertensive patients with
atherosclerotic coronary disease
Aly M. Hegazy, M.D. and Aly Ramzy,
M,D.
The
aim of this study was the evaluation of coronary collateral
circulation in relation to the presence of systemic
hypertension and left ventricular hypertrophy. One hundred
patients with significant coronary artery disease (>75%)
were enrolled in the study. Thirty-five hypertensive
patients with left ventricular hypertrophy (LVH) were
considered as group I, 35 hypertensive patients without
LVH as group II and 30 normotensive patients as group
III. Coronary angiography was done for all patients.
Class 0: no collaterals, class I: partial filling and
class II: complete filling of collaterals were used
as angiographically classified coronary collaterals.
Echocardiography and graded exercise ECG test were done
for all patients. There was a non-significant difference
between hypertensive and normotensive patients as regards
clinical characteristics. There was a significantly
increased number of patients with class II collaterals
(p <0.01) among hypertensive patients compared to
normotensive patients. There was a non-significant difference
between the 3 groups of the study as regards coronary
artery disease and stenosis, but there were significantly
more proximal lesions in patients with class II collaterals
(p<0.0 1) and increases distal lesions in patients
without collaterals (p<0.01). There was a significant
increase in coronary perfusion pressure (p<0.0 1)
in patients with class I and II collaterals. There was
a non significant difference between the patients of
the 3 study classes as regards the systolic function
of the left ventricle and segmental wall motion abnormalities,
but there was significantly increased left ventricular
mass (LYM) and LVM index (p<0.0l) in the patients
of class II than those of class I and class 0. There
was a non-significant difference in functional capacity
inpatients of class II, I and 0 as there was a non significant
difference between the 3 classes of the study as regards
the Canadian functional classification, exercise tolerance
and ST segment depression.
We
concluded that patients with systemic hypertension and
coronary artery disease have an increase in coronary
collateral circulation corresponding to the left ventricular
hypertrophy and that the functional capacity of coronary
collateral circulation is not augmented by left ventricular
hypertrophy.
Abstract
presented in the 2nd meeting of the Egyptian
Hypertension Society, 1996
CARDIAC
CYTOPROTECIVE PROFILE OF SOME
ANTI-HYPERTENSIVES IN RATS A CORRELATION
OF THEIR CARDIAC ANTIOXIDANT-BUFFERING
CAPAClTY TO THEIR RELATED RESPIRATORY
ENZYMES.
Nayel O*, and Youssif M** * Pharmacology
& Drug
Toxicology Departme, Faculty of Medicine, **
Histochemistry & Cell Biology Department, Medical
Research Institute, Alexandria University.
Cardioprotection,
vasculoprotection and the possession of inherent antioxidant
buffering capacity are recent requisites to be fulfilled
in an idea antihypertensive agent. No wonder, the objectives
of this study focused on questioning the impact of some
available antihypertensives, on cardiac respiratory
enzymes, probing in their possible correlative ability
to modulate the cardiac antioxidant buffering capacity
particularly when binge subjected to peroxidative stress
[Hypercholesterolaemia being taken as a model].
The
60 male albino rats experimented comprised; 10 normal
controls (N) receiving 2% gum acacia daily, 10 oxidatively
stressed gp. (S) receiving atherogenic diet, 40 rats
oxidatively stressed while continuously receiving either;
Amlodipine 5mg/kg/day (S+A)(n=10), or Isradipine 2mg/kg/day
(S+I)(n=10), or Captopril 35mg/kg/day (S+c)(n=l0) or
fosinopril 8 mg/kg/day. (S+F)(n=10) for 2 months.
Result
revealed that (S) suppressed cardiac cytochrome oxidase,
succinic dehydrogenase, ATPase and increased lactate
dehydrogenase enzyme activities compared to (N), as
assessed hi stochemically. It meanwhile Significantly
depleted cardiac enzymatic antioxidant buffering capacity
as judged by SOD and catalase activities and significantly
increased lipid peroxidation as indexed by MDA seruin
levels that were assessed biochemically. On the other
hand. The studied antihypertensives variably conferred
cardioprotection, where S+I>S+A and S+C>S+F succeeded
to revert all cardiac enzymes assessed histocheinically
toward (N) as compared to (S)
They
also significantly variably elevated cardiac antioxidant
buffering capacity and decreased lipid peroxidation
when compared to (S).
The
underlying mechanism behind the variable cardiocytoprotective
potentials of the studied antihypertensives are discussed
and the impact of this on their clinical utility is
raised. International Conference of: Infectious Diseases
& Public Health. A research & Clinical Update
Conference Hall, Alexandria, Egypt.
17-20
October 1997.
Do You Know That?
Therapeutic trends embark the use of;
Short-term
high-dose combination of oral antioxidant supplementation
[ 200 mg zinc sulphate, 500 mg of ascorbic acid 600
mg of tocopherol and 30 mg carotene I to hypertensives
[ median basal SP being 165 nun Hg] for ~ weeks,
aside their usual dietary! habits and regular unaltered.
Diagnostic
Utilities Imply
Knowing
the presence of a handy BP miniature monitor about the
size of a deck of cards, that measures arterial pressure
in left index finger by a process called "Photoelectric
Oscillometry. It is called HEM-808F compact antihypertensives
therapy, was able to significantly reduce blood pressure.
This is possibly through achieved through increased
availability of NO by removing superoxide anion. This
may have implications for the innovative use of antioxidants
as adjutants to conventional antihypertensive therapy.
Clin
Sci 1997, 92, 361-5.
Finger
blood pressure monitor. Also available, is another form
that can be strapped around the wrist. These devices
are only developed for people who keep close tabs on
their blood pressure.
Modern
Med Mid East 1997:14(6): :27.
EHS NEWS
The
EHS newsletter has a new editorial hoard During the
annual Ramadhan meeting of this year, Prof. Dr.
M. Mohsen Ibrahim called upon all those who
were interested to join. Dr. Mohammed Hamed remains
our editor in chief Dr. Abdel Mooty El Keiy
and Dr. Zeinab Ashour remains assistant
editors. We would like to welcome the new members of
the editorial board, Dr. Fawzia El Demerdasli,
Professor of Cardiology, Mansoura University, Dr.
Omnia Nayel, Professor of Pharmacology, Alexandria
University. Dr. Alia Abdel Fattah. Assistant
Professor of Critical Care Medicine, Cairo University
and last hot not least. Magdy Saba, Cardiology,
Resident at Cairo University.
CALENDAR
| Assessment
of vascular function, Background ,methods and clinical
relevance |
Sophia
Antipolis. France, 22-24 January 1998 |
Contact:
European Heart house, 2035 route des Colles, les
Templiers 06903 Sophia Antipolis Cedex Tel
04 9294 7600 |
| 25th
annual meeting of the Egyptian Society of Cardiology |
Cairo,
Mariott Cairo, 22-27 February, 1998 |
Contact:
Prof. Osama Abdel Aziz, 98 Mohammed
Farid street.
Tel (202)
360 2800 |
| 23rd
international joint conference on stroke |
Orlando,
USA
5-7 February,
1998 |
Contact:
American heart
association
7272, Greenville
Ave, Dallas
TX 75231, USA
Tel (1-214)
706 11 00 |
The GlobaL Actions of
Lacidipine
A new out look to matters, dears that a tenuous balance
between steady state level of NO & reactive oxygen
species [ROS] is essential to opdmize endothelial dependant
vascular relaxation [EDVR], while any dismpthon in such
balance predispose to dysfunction characteristic to many
diseases as hypertension, atherosclerosis, diabetes, CHF....
etc.
Within
this insight it was questioned, whether long term antihypertensive
therapy targeted to normalize or at least improve endothelial
dysfunction may reduce atherdsclerosis in hypertensives
by virtue of such effect, or whether this is more obvious
only by classes of antihypertensives possessing antiathero
- sclerotic effects, as for example lacicipine.
No
wonder, this drug was enrolled in the European Lacidipine
Study on AtheroscIerosi,~ [ELSA] conducted on mild
to moderate hypertensives whom were stratified according
to the presence of carotid plaques or the presence or
absence of intimd-medial carotid thickening. The objective
was to contrast the effects of lacidipine versus atenolol
on BP control [assessed by .ABPMJ. on carotid vessel
progressive or retiressive modifications [assessed by
B-mode ultra-sonography] & on incidence of CV events
throughout a 5 years follow up period.
The
metabolically neutral molecule of lacidipine was chosen,
as it innovative characteristics. Thus, its high lipophilicity
& binding affinity allows for prolonged contact
to its specific receptors, while its high membrane partition
coefficient permits its deep anchor in biomembranes
to block the inactive site of Ca channels. This aside
its ideal pharmacokinetics [peak:trough ratio
>6011/01,
Mil all exert a potent, gradual, smooth, effective &
sustained BP controls. By the same potentialities, it
also exerts some anti atherogenic effects through blocking
Ca dependent processes involved in plaque formation
& progression as; cholesterol accumulation in macrophages,
platelet aggregation, smooth muscle migration, proliferation
& release of growth & chemotactic factors, ECM
formation.., etc.
Beyond
this, the unique structure & deep insertion of lacidipine
in cell membranes permits its positioning near the double
bonds most highly susceptible to peroxidative attack
by ROS. This ranked the drug equipotent to Vit E as
an antioxidant, to chain break autocatalytic alkoxyl
& peroxyl radicle reactions, to prevent lipid peroxidat
ion & to curtail LDL oxidation. minimizing its sequelac
on plaque progression. Moreover this antioxidant capacity
is abet to set back the balance of NO I ROS optimum
enough to preserve EDYR thus controlling the vasomotor
deficits characteristic to hypertension & atherosclerosis
which contribute much to their clinical complications
as; ischaemic LV dysfunction. AMI & CHF.
By
highlighting such utilities, one can realize how lacidipine
as 2-4mg once daily can globally encompass the pathobiological
continuum of hypertension & atherosclerosis.
References:
Atherosclerosis
1989;80; 17-26
Free Radic Biol Mod 1992; 12:183-7.
J Cardiovasc Pharmacol 1995; 25(Suppl. 3) SI 1-6.
Biochem Pharn4 19%;51 (6);81 1-19.
Clin Cardiol 1997,20(11) [Suppl II]:11-17.
Clin Cardiol 1997,20 (11) [Supo II]:26-33.
