nstantaneous and historical temperature effects on a-pinene
Dose related effects of nicotine on
oxidative injury
in young, adult and old rats
Author Details
Anshu Jain
Division
of Pharmacology and Toxicology, Defence Research
and Development, Establishment,
Jhansi Road, Gwalior - 474 002, India
S.J.S.Flora
(Corresponding author)
Division of Pharmacology and Toxicology, Defence
Research and Development, Establishment,
Jhansi
Road, Gwalior
- 474 002, India
e-mail: sjsflora@hotmail.com
Publication Data
Paper received:
18
January 2011
Revised
received:
26
March 2011
Accepted:
21 April 2011
Abstract
Nicotine
affects a variety of cellular process ranging from induction of gene
expression to secretion of hormones and modulation of enzymatic activities.
The objective of the present study was to study the dose dependent toxicity
of nicotine on the oxidative stress in young, adult and old rats which were
administered 0.75, 3 and 6 mg kg-1 nicotine as nicotine hydrogen tartarateintraperitoneally for
a period of seven days. No changes were observed in blood catalase
(CAT) activity and level of blood reactive oxygen species (ROS) in any of the
age group at the lowest dose of nicotine. However, at the highest dose (6 mg
kg-1 nicotine) ROS level increased significantly from 1.17to
1.41?M ml-1 in young rats and from 1.13 to 1.40 ?M ml-1
in old rats. However, no change was observed in blood ROS levels of adult
rats. Administration of 3 mg kg-1 nicotine resulted in an increase
in level of reduced glutathione (GSH) in rats of all the age groups. The
young animals were the most sensitive as a dose of 6 mg kg-1
resulted in decline in the levels of reduced GSH to 0.89 mg ml-1
as compared to normal control (1.03 mg ml-1). The antioxidant
enzymes SOD and CAT were sensitive to a dose of 6 mg kg-1 as it
resulted in decline of the enzymatic activity in all age group animals. Also,
administration of nicotine at a lower dose of 3 mg kg-1 inhibited
SOD activity from 1.48 to 1.20 units min-1 mg-1
protein in old rats. Catalase activity showed a
similar trend at a dose of 3 mg kg-1. Administration of nicotine
also increased the blood lipid peroxidation levels
at all three doses in young and old rats dose
dependently. Nicotine exposure also increased ROS in brain at the doses of 3
and 6 mg kg-1 in all the three age groups. Brain GSH decreased
significantly at high dose of nicotine (6 mg kg-1b.wt.) in adult rats (4.27 mg g-1) and old
rats (3.68 mg g-1) but in young rats level increased to 4.40 mg g-1
at the lower dose (0.75 mg kg-1 nicotine). Brain lipid peroxidation increased at all three doses of nicotine in
young as well as old rats as compared to their respective normal control. The
SOD activity increased significantly in young (2.88 units
min-1mg-1 protein) and old rats (1.81 units min-1mg-1
protein) as compared to their respective normal at a dose of 6 mg kg-1.
Interestingly, the SOD activity decreased in adult rats (2.18 units min-1mg-1
protein) as compared to its normal control. Catalase
activity decreased at the dose of 3 mg kg-1 and 6 mg kg-1
nicotine in young and old rats but no effect was observed in adult rats at
any of the doses. Acetylcholine esterase (AchE)
activity decreased in a dose dependent manner in adult and old rats. Overall,
the results of the study indicate that young and old rats are more sensitive
to nicotine induced oxidative stress as compared to the adult ones.
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