CONTENTS

J. Duhok Univ., Vol.14, No.1 (Pure and Eng. Sciences), Pp 30-38, 2011
oxidative damage. The reactive species
scavenged by vitamin C include superoxide,
aqueous peroxyl radicals, singlet oxygen, ozone,
peroxynitrite, nitrogen dioxide, and
hypochlorous acid (Halliwell,1996). Attri et al.,
(2003) concluded that concomitant
administration of vitamin C ameliorates HTN,
and normalizes NO levels. Compared with
control group, blood Pb level was decreased
significantly after given vitamin C, vitamin E or
combination of vitamin C and E. The
concentrations of superoxide dismutase, NO and
NOS were significantly higher in vitamin C
and/or E groups than those in control group
(Li et al., 2008)
The effects of co-administration of melatonin
with vitamin C and E on SBP are not examined
yet. Therefore, the aim of the present study was
to investigate the effects of long-term
administration of melatonin, vitamin C, vitamin
E and in combinations, on BP, serum NO
,calcium ions ,electrolytes and body weight gain
or loss in lead-induced hypertensive rats.
MATERIALS AND METHODS
Animals and housing
Fifty four adult female albino rats (Rattus
norvegicus) were used in this study. All rats
were weighing about (240 - 280 gm) and (7-9)
weeks of age at the time when the experiment
started. Animals were housed in plastic cages
bedded with wooden chips. They were housed
under standard laboratory conditions, 12:12
light/dark photoperiod at 22 ± 2 ºC. The
animals were given standard rat pellets and
tap water ad libitum.
Experimental Design
This experiment was planed to study the
effects of melatonin, vitamin E ,vitamin C and
their combinations on SBP, heart rate, serum
NO, sodium, potassium , calcium and body
weight in rats treated with lead acetate. The
experimental rats were divided to nine groups,
each with six individuals and the treatments
were continued for 10 weeks as the following:
Group 1: Control. The rats were given standard
rat chow and tap water ad libitum.
Group 2: Sodium acetate . The rats were given
standard rat chow and sodium acetate at dose
(0.1mg/L drinking water).
Group 3: Lead acetate (Pb). The rats were given
standard rat chow and lead acetate at dose
(0.1mg/L drinking water).
Group 4: Pb + Melatonin. The rats were
supplied with standard rat chow with melatonin
(60 mg/kg diet) and Pb
Group 5: Pb +Vitamin E. The rats were supplied
with standard rat chow with vitamin E (1000
I.U/kg diet) and Pb
Group 6: Pb +Vitamin C. The rats were given
standard rat chow with Pb and vitamin C at dose
(1mg/L drinking water).
Group 7: Pb + Melatonin + Vitamin E. The rats
were supplied with standard rat chow with
melatonin , vitamin E and Pb.
Group 8: Pb + Melatonin +Vitamin C. The rats
were supplied with standard rat chow with
melatonin , vitamin C and Pb.
Group 9: Pb +Vitamin E+ Vitamin C. The rats
were supplied with standard rat chow with
vitamin E , vitamin and Pb.
Collection of blood samples
At the end of the experiment, the rats were
anesthetized with ketamine hydrochloride (50
mg/kg). Blood samples were taken by cardiac
puncture into chilled tubes and centrifuged at
3000 rpm for 20 minutes; then sera were stored
at -85C 0 until assay.
Blood pressure and heart rate measurements
Measurements of SBP and heart rate were
obtained each two weeks by the tail-cuff method
in all groups using power Lab (AD Instruments,
power lab 2/25). During the week before
treatment the rats were trained to become
accustomed to the blood pressure measurements.
Rats were placed in a restraining chamber and
warmed to an ambient temperature of
approximately 37C o , typically taking about 10-
15 minute after that occluding cuffs and
pneumatic pulse transducers were placed on the
rats' tails. Six readings were taken for each rat,
the highest, lowest and any associated with
excess noise or animal movement were
discarded. The average was taken of the
remaining readings to generate a value for a
given rat for that week.
BIOCHEMICAL DETERMINATION
Determination of serum sodium, potassium
and calcium ion concentrations
Serum Na + and K + ion concentrations were
determined by using flame photometer
(Galenkamp Flame Analyzer, Germany). Serum
calcium was determined by spectrophotometer
calcium kit Serum total nitric oxide
measurement Serum total NO was
determined by NO non –enzymatic assay kit
(US Biological, USA)
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