Increasing matrix metalloproteinase-2 activity by treatment of ovine cervical explants with a long-acting analogue of oxytocin (Carbetocin) at the expected time of artificial insemination.

Abstract

The aim was to study the effect of long-acting analogue of oxytocin (Carbetocin) on cervical collagenolysis of MAP-eCG synchronized ewes. At the expected time of artificial insemination, five ewes were slaughtered (n = 5) and their cervical explants (100-200 mg) were incubated during 12 h with MEM supplemented with 0, 8, 16, 32 and 64 ng/mL of Cb. Activities of activated and latent forms of matrix metalloproteinases-2 and - 9 (MMP-2 and MMP-9, respectively) in the supernatant were determined by a SDS-PAGE zymography and prostaglandin E2 concentration by immunoassay. Data were analyzed by ANOVA test. The MMP-9 activity was detected weakly and sporadically. The activity of activated MMP-2 was higher in 32 ng/mL Carbetocin treated samples than in untreated samples (P < 0.03). The activity of latent MMP-2 tended to be higher in 32 ng/mL than in 8 ng/mL Carbetocin treated samples (P = 0.083). The activated/latent ratio of MMP-2 tended to be higher in 64 ng/mL Cb treated samples than in untreated samples (P = 0.089). Prostagladin E2 concentration was not affected by Carbetocin dose. The data show that Carbetocin treatment of cervical explants induces an increase in MMP-2 activity by prostaglandin E2-independent mechanisms, suggesting Carbetocin as a potential inducer of cervical dilation in sheep.