Presence of LDL modified by myeloperoxidase in the penis in patients with vascular erectile dysfunction: a preliminary study.
OBJECTIVE
Erectile dysfunction (ED) is a major vascular disorder. Atherosclerosis is closely related to lipoprotein metabolism and especially, oxidative modifications of low-density lipoproteins (LDLs), which are involved in early development of the atherosclerotic lesions. Current major questions include how LDLs are oxidised (OxLDL) in vivo. Myeloperoxidase (MPO) is an enzyme present in the azurophile granules of neutrophils and monocytes that can contribute to LDL oxidation in the presence of H(2)O(2). We have developed a new monoclonal antibody against LDL modified by MPO (Mox-LDL) and have used it on penile biopsies from patients operated on for penile implant.


METHODS
Seven patients with vascular ED and one impotent patient after radical prostatectomy (RP) underwent biopsy of the cavernous body during penile implant procedures. An immunohistochemical study with a monoclonal antibody against Mox-LDL and an antibody against apoprotein B (ApoB), the protein moiety of LDL, to confirm the presence of LDL was performed.


RESULTS
The staining was positive for Mox-LDL and ApoB and was present between the endothelial cells of the sinusoid spaces and the smooth muscle cells in the seven patients with vascular ED. The patient with RP was negative for Mox-LDL.


CONCLUSIONS
Because it is known that modified LDL could decrease nitric oxide production, Mox-LDL could be one of the agents responsible for ED. Further studies are needed to confirm this hypothesis.
Zouaoui Boudjeltia
Karim
K
Experimental Medicine Laboratory, ULB 222 Unit, ISPPC, CHU de Charleroi, Hôpital A. Vésale, Montigny-Le-Tilleul, Belgium.
Roumeguere
Thierry
T
Delree
Paul
P
Moguilevsky
Nicole
N
Ducobu
Jean
J
Vanhaeverbeek
Michel
M
Wespes
Eric
E
D000368:Aged; D001055:Apolipoproteins B / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000150:complications; D007172:Erectile Dysfunction / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D018783:Impotence, Vasculogenic / Q000150:complications / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D010413:Penis / Q000378:metabolism*; D009195:Peroxidase / Q000378:metabolism*
D001055:Apolipoproteins B; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D009195:Peroxidase