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

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.