Transdermal oestradiol replacement therapy enhances platelet constitutive nitric oxide synthase activity in postmenopausal women with type 2 diabetes mellitus.
OBJECTIVE
To determine whether treatment with transdermal oestrogen replacement therapy (TERT) in postmenopausal women with type 2 diabetes mellitus was able to increase the activity of constitutive nitric oxide synthase (cNOS) in platelets.


METHODS
Eighteen postmenopausal women with type 2 diabetes mellitus (group A) were studied in basal conditions (A1) and on the 10th day of the third month of a sequential opposed TERT (A2) evaluating platelet cNOS activity measured by the conversion of radiolabelled l-arginine to l-citrulline. As a control group (B) 25 normal postmenopausal women underwent the same treatment (B1 and B2 before and during treatment, respectively).


RESULTS
Basal values of platelet cNOS activity were superimposable (0.6 +/- 0.1 vs. 0.7 +/- 0.1 fmol/min/109 plts, NS). During TERT, platelet cNOS activity rose in A and B (0.6 +/- 0.1 vs. 1.8 +/- 0.1 fmol/min/109 plts, P < 0.05 and 0.7 +/- 0.1 vs. 2.4 +/- 0.2, P < 0.001, A1 vs. A2 and B1 vs. B2, respectively). However, platelet cNOS activity of A2 did not reach the values of B2 (1.8 +/- 0.1 vs. 2.4 +/- 0.2 fmol/min/109 plts, P < 0.05; A2 vs. B2, respectively).


CONCLUSIONS
Sequential opposed transdermal oestrogen replacement therapy was able to increase platelet cNOS activity in postmenopausal women with type 2 diabetes mellitus, suggesting that its use might be positive in preventing cardiovascular pathologies.
Department of Internal Medicine, University of Turin, Italy. martinavalentino@hotmail.com
Valentino
V
Martina
Guido Albino
GA
Bruno
Carla
C
Origlia
Daniela
D
Gaia
Fulvia
F
Trucco
Gianpiero
G
Pescarmona
D000279:Administration, Cutaneous; D001792:Blood Platelets / Q000201:enzymology*; D003924:Diabetes Mellitus, Type 2 / Q000201:enzymology*; D004958:Estradiol / Q000494:pharmacology; D015914:Estrogen Replacement Therapy; D005260:Female; D005342:Fibrinolysis / Q000187:drug effects; D006442:Glycated Hemoglobin / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008055:Lipids / Q000097:blood; D008875:Middle Aged; D019001:Nitric Oxide Synthase / Q000097:blood / Q000187:drug effects*; D052250:Nitric Oxide Synthase Type III; D017698:Postmenopause / Q000097:blood*
D004958:Estradiol; D006442:Glycated Hemoglobin; D008055:Lipids; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496314:NOS3 protein, human