Leptin receptor in boar spermatozoa.

Leptin is active in both metabolism and reproduction. In fact, it seems to exert an inhibitory action on gonadal functions by reducing testosterone production. The presence of leptin in human and boar seminal plasma and in human spermatozoa has been demonstrated; recently, leptin receptors (Ob-R) have been localized in human spermatozoa, thus suggesting a possible action of this hormone even on these cells. Our aim was to verify whether leptin receptor [the long form (Ob-Rb)] is present in boar spermatozoa. Immunofluorescence and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques were employed. RNA was extracted from boar spermatozoa and a specific band (382 bp) for Ob-Rb was detected after RT-PCR. Ob-Rb was detected on acrosome, subequatorial area and either on the midpiece or on the whole tail. These localizations were maintained even in semen washed twice to eliminate seminal plasma. We conclude that Ob-R is present in boar spermatozoa where seminal plasma leptin can exert its effects.