Systemic and renal effect of nicotine in non-smokers: influence of vitamin C.
OBJECTIVE
To investigate whether the administration of the anti-oxidant vitamin C could prevent the systemic and renal effects of nicotine in healthy non-smoker volunteers.


METHODS
The acute effects of oral, 4 mg, nicotine gum (n = 10), intravenous vitamin C (12 mmol, n = 8) or both (n=9) on mean arterial pressure (MAP), heart rate, glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and urinary cyclic guanosine monophosphate (cGMP) were assessed in non-smokers.


RESULTS
In subjects receiving nicotine, MAP (+8 +/- 4 mmHg, P<0.0001) and HR (+13 +/- 8 beats/min, P < 0.001) increased whereas ERPF (-65 +/- 69 ml/min per 1.73 m2, P < 0.01), GFR (-14.5 +/- 16.8 ml/min per 1.73 m2, P < 0.01) and cGMP (-180 +/- 173 pmol/min, P < 0.01) decreased as compared to baseline values. The concomitant administration of nicotine and vitamin C caused similar haemodynamic changes; however, cGMP remained unchanged. In subjects receiving only vitamin C, there were no significant changes in MAP, heart rate, ERPF, GFR and cGMP.


CONCLUSIONS
The present findings indicate that vitamin C was unable to prevent the renal vasoconstriction, but it prevented the fall in cGMP provoked by nicotine in non-smokers. This suggests that nicotine induces a degradation of nitric oxide mediated by oxygen-derived free radicals which may be prevented by vitamin C administration. The nicotine-induced renal vasoconstriction may be related to other mechanism(s).
Halimi
J M
JM
Department of Medicine, Centre Hospitalier Universitaire, Montpellier, France.
Mimran
A
A
D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects; D006152:Cyclic GMP / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006977:Hypertension, Renal / Q000503:physiopathology; D008297:Male; D009538:Nicotine / Q000008:administration & dosage*; D018722:Nicotinic Agonists / Q000008:administration & dosage*; D012079:Renal Circulation / Q000187:drug effects*; D012907:Smoking
D000975:Antioxidants; D018722:Nicotinic Agonists; D009538:Nicotine; D006152:Cyclic GMP; D001205:Ascorbic Acid