Relationship between vascular damage degrees and endothelial progenitor cells in patients with erectile dysfunction: effect of vardenafil administration and PDE5 expression in the bone marrow.
OBJECTIVE
To evaluate the levels of circulating progenitor cells (PCs) and the effect of a single dose of vardenafil 20mg on the number of these cells in men with erectile dysfunction (ED) and various degree of vascular injury at the carotid artery level.


METHODS
Sixty-eight patients with ED and various degree of carotid damage, and 25 controls were enrolled. Patients were divided into three groups according to their intima media thickness (IMT) status (normal, mild increase, or plaque). All subjects received vardenafil 20mg, and evaluation of the number of circulating PCs was performed at baseline and 4h after vardenafil administration. An RNA expression analysis of phosphodiesterase type 5 (PDE5) on bone marrow was also performed.


RESULTS
We found a significant reduction of circulating PCs in ED patients with respect to controls and a reduction in PC counts in patients with mild IMT increase or plaque, but not in those with normal IMT. Four hours after vardenafil administration we observed an increase in the number of PCs in all patients and controls. Reverse transcriptase-polymerase chain reaction analysis showed that human bone marrow expresses PDE5 messenger RNA.


CONCLUSIONS
Patients with ED and a low number of circulating PCs may be considered at increased risk for an endothelial dysfunction. An impaired response to vardenafil stimulus may be proposed as a surrogate marker of a patient's endothelial regenerative ability.
Foresta
Carlo
C
Department of Histology, Microbiology and Medical Biotechnologies, Centre for Male Gamete Cryopreservation, University of Padova, Via Giustiniani 2 c/o Palafellin, 35121 Padua, Italy. carlo.foresta@unipd.it
Caretta
Nicola
N
Lana
Andrea
A
De Toni
Luca
L
Biagioli
Andrea
A
Vinanzi
Cinzia
C
Ferlin
Alberto
A
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism*; D001772:Blood Cell Count; D001854:Bone Marrow Cells / Q000378:metabolism*; D002340:Carotid Artery Diseases / Q000150:complications / Q000473:pathology*; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D042783:Endothelial Cells / Q000187:drug effects / Q000473:pathology*; D004730:Endothelium, Vascular / Q000473:pathology; D007172:Erectile Dysfunction / Q000150:complications / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology*; D013234:Stem Cells / Q000187:drug effects / Q000473:pathology*; D013450:Sulfones / Q000494:pharmacology; D014227:Triazines / Q000494:pharmacology; D000069058:Vardenafil Dihydrochloride; D014665:Vasodilator Agents / Q000494:pharmacology*
D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D013450:Sulfones; D014227:Triazines; D014665:Vasodilator Agents; D000069058:Vardenafil Dihydrochloride; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517381:PDE5A protein, human