RESUMO
It has been postulated that cytokines play an immunoregulatory role in human semen. The presence and levels of various cytokines, namely the interleukins 6, 10 (IL-6 and IL-10) and tumor necrosis factor alpha (TNFalpha) were investigated in the seminal plasma of six fertile crossbred bulls (Bos taurus x Bos indicus), using specific enzyme immunoassay. Cytokine levels were related to the semen quality of these bulls. A direct significant correlation between the level of IL-10 and individual sperm motility (r=0.84, P<0.036) was observed. The levels of IL-6 and IL-10 were inversely correlated (r=-0.93, P<0.006) and likewise in the same way an inverse correlation between the level of IL-6 and TNFalpha was observed (r=-0.84, P<0.037). These results confirm that cytokines are present in bull semen as has been demonstrated in human semen.
