COMPARATIVE EFFECTS OF 6-WEEK NICOTINE TREATMENT ON BLOOD-PRESSURE AND COMPONENTS OF THE ANTIOXIDANT SYSTEM IN MALE SPONTANEOUSLY HYPERTENSIVE (SHR) AND NORMOTENSIVE WISTAR-KYOTO (WKY) RATS
Lm. Bui et al., COMPARATIVE EFFECTS OF 6-WEEK NICOTINE TREATMENT ON BLOOD-PRESSURE AND COMPONENTS OF THE ANTIOXIDANT SYSTEM IN MALE SPONTANEOUSLY HYPERTENSIVE (SHR) AND NORMOTENSIVE WISTAR-KYOTO (WKY) RATS, Toxicology, 98(1-3), 1995, pp. 57-65
Hypertension, cigarette smoking, and nicotine augment the clinical sig
nificance bf other risk factors associated with cardiovascular disease
s by mechanisms which are poorly understood, Since altered trace eleme
nt metabolism and antioxidant status have also been implicated in thes
e diseases, the present study investigated the interaction of nicotine
treatment and hypertension on tissue trace element concentrations and
select indices of antioxidant status. Spontaneously hypertensive (SHR
) and normotensive Wistar Kyoto (WKY) rats were treated with nicotine,
via a time release tablet at an average rate of 75 mu g/h for 6 weeks
, Systolic blood pressure in nicotine-treated SHRs was significantly h
igher at weeks 3 and 6 of treatment than in the SHR-controls, Blood pr
essure in WKY rats was not affected by nicotine. Plasma and liver iron
concentrations in the nicotine-treated SHR were higher than the SHR-c
ontrols and the WKY groups. Nicotine treatment did not affect plasma a
nd liver zinc and copper concentrations or liver manganese (Mn) concen
trations, Plasma ceruloplasmin activity was increased by nicotine trea
tment in the SHRs, Liver Mn superoxide dismutase (MnSOD) activities an
d glutathione concentrations, and liver and heart glutathione reductas
e activities, were higher in both groups of SHRs than in the WKY group
s. Red cell SOD activity in the nicotine-treated SHR was lower than in
the SHR-controls. In summary, blood pressure increased more rapidly i
n the nicotine-treated SHRs compared to the controls, The marked effec
ts on antioxidant status observed were attributable more to hypertensi
on than to the nicotine treatment.