Effects of tibolone on plasma levels of nitric oxide in postmenopausal women.
OBJECTIVE
To determine the effects of tibolone on nitric oxide (NO) plasma levels in postmenopausal women.


METHODS
Randomized, double-blind, placebo-controlled, cross-over trial.


METHODS
Healthy volunteers in an academic research environment.


METHODS
Eighteen healthy women who have been in postmenopause for 1-4 years.


METHODS
Women received either tibolone 2.5 mg/day (group A) or placebo (group B) for 1 month; then the treatment was inverted for the second month.


METHODS
Plasma concentration of NO stable oxidation products and blood pressure were evaluated at baseline, month 1, and month 2.


RESULTS
Baseline concentration of NO metabolites were similar in both groups. At month 1, mean concentration of NO metabolites increased significantly in group A alone. At the end of month 2, NO metabolite levels in group A returned to baseline, whereas in group B they increased significantly.


CONCLUSIONS
Tibolone induced a sustained increase in plasma levels of NO in postmenopausal women, suggesting that tibolone may exert a direct cardiovascular protective effect in postmenopausal women.
Cicinelli
Ettore
E
First Unit of Obstetrics and Gynecology, University of Bari, Italy. Cicinelli@gynecology1.uniba.it
Ignarro
Louis J
LJ
Galantino
Pietro
P
Pinto
Vincenzo
V
Barba
Bruno
B
Schonauer
Sergio
S
D018592:Cross-Over Studies; D004311:Double-Blind Method; D020847:Estrogen Receptor Modulators / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood*; D009652:Norpregnenes / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010919:Placebos; D017698:Postmenopause / Q000097:blood*; D012016:Reference Values; D013997:Time Factors
D020847:Estrogen Receptor Modulators; D009652:Norpregnenes; D010919:Placebos; D009569:Nitric Oxide; C027385:tibolone