Cyclic nucleotide phosphodiesterase inhibition increases tyrosine phosphorylation and hyper motility in normal and pathological human spermatozoa.
Our objective was to determine the effect of phosphodiesterase (PDE) inhibition on: 1) tyrosine phosphorylation of human spermatozoa at the tail level; and 2) sperm motion parameters and hyperactivated motility. The study was conducted with normozoospermic and asthenozoospermic samples incubated under in vitro capacitating conditions. The main outcome measures were computer-assisted sperm motion analysis and fluorescent immunodetection of phosphotyrosine-containing proteins. Pentoxifylline (PTX) was used as PDE inhibitor because of its wide use in the clinic. PTX-treatment significantly increased sperm velocity, hyperactivated motility and tyrosine-phosphorylation, both in normo and asthenozoospermic samples. Tyrosine-phosphorylation of tail proteins was highly conspicuous in both types of samples, showing no differential pattern after PTX-treatment. Normozoospermic samples treated with pentoxifylline showed an increase in the number of spermatozoa displaying hyperactivated movement and tyrosine-phosphorylation at the tail level. Preliminary data on asthenozoospermic samples exhibiting altered motion characteristics and defective phosphorylation of sperm-tail proteins showed that both defects can be concomitantly overcome by pentoxifylline treatment. Tyrosine-phosphorylation of sperm-tail proteins is underlying the enhancement of hyperactivated motility resulting from PDE inhibition by pentoxifylline.
Yunes
Roberto
R
The Jones Institute for Reproductive Medicine, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk, VA, USA. ryunes@fcm.uncu.edu.ar
Fernández
Pedro
P
Doncel
Gustavo F
GF
Acosta
Aníbal A
AA
D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D010431:Pentoxifylline / Q000494:pharmacology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D013081:Sperm Motility / Q000187:drug effects*; D013082:Sperm Tail / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D014443:Tyrosine / Q000378:metabolism*
D010726:Phosphodiesterase Inhibitors; D014443:Tyrosine; D010431:Pentoxifylline