Effects of milrinone and butyrolactone-I on porcine oocyte meiotic progression and developmental competence

Abstract

Inappropriate coordination of oocyte nuclear and cytoplasmic maturation is thought to contribute to the poor efficiency of embryo production in vitro. With the aim of improving this coordination, the effects of milrinone, an inhibitor of type 3 phosphodiesterases, and butyrolactone-I, a selective inhibitor of cdc2 kinases, on porcine oocyte maturation were investigated. Oocytes recovered from slaughterhouse-derived ovaries of prepubertal animals were treated with the inhibitors for 24 h. At concentrations of 50 and 250 microm, milrinone reversibly inhibited meiotic progression in 57% and 71% of oocytes, respectively. The presence or absence of milrinone in the medium used to wash oocytes for 30 min did not alter the inhibitory effect of the 24 h treatment. At concentrations of 25 and 50 microm, butyrolactone-I inhibited meiotic progression in 61% and 66% of oocytes, respectively, but the effect was not fully reversible in the absence of follicle-stimulating hormone (FSH). The presence of FSH during the butyrolactone-I treatment period increased the ability of oocytes to subsequently complete meiosis at 44 h without changing the inhibitory effect at 24 h. Following in vitro fertilisation at 44 and 50 h, treatment with butyrolactone-I and milrinone, alone or in combination, did not alter embryo cleavage rate, blastocyst formation rate or blastocyst cell number. Despite the different actions of milrinone and butyrolactone-I, the present study demonstrates that these reagents inhibit meiotic progression to a similar extent in the presence of FSH while maintaining developmental competence in porcine oocytes.

The Effect of Cilostamide on Gap Junction Communication Dynamics, Chromatin Remodeling, and Competence Acquisition in Pig Oocytes Following Parthenogenetic Activation and Nuclear Transfer1

“…Many of these strategies, often referred to as 'prematuration culture', are based on the temporary blockage of oocyte spontaneous meiotic resumption, by modulating intra-oocyte cAMP content with different agents such as cAMP analogues or PDE inhibitors [12,16,[20][21][22][55][56][57][58][59][60][61][62][63][64][65][66][67]. Our results on the effect of the use of PDE inhibitors on meiotic resumption are largely supportive of previous data in pre-pubertal gilts in which cilostamide or other PDE3 inhibitors, such as milrinone, have been used [17,67,68].…”

“…Many of these strategies, often referred to as 'prematuration culture', are based on the temporary blockage of oocyte spontaneous meiotic resumption, by modulating intra-oocyte cAMP content with different agents such as cAMP analogues or PDE inhibitors [12,16,[20][21][22][55][56][57][58][59][60][61][62][63][64][65][66][67]. Our results on the effect of the use of PDE inhibitors on meiotic resumption are largely supportive of previous data in pre-pubertal gilts in which cilostamide or other PDE3 inhibitors, such as milrinone, have been used [17,67,68]. Effects of cilostamide treatments on in vitro developmental potential have been tested in human [20,21,63], bovine [22,64], ovine [65] and mouse [56,62,64,69] with different outcomes depending on the species, the time of COC incubation with cilostamide, the combination with other agents and the experimental approach itself.…”

Meiotic inhibition of bovine oocytes in medium supplemented with a serum replacer and hormones: effects on meiosis progression and developmental capacity

“…Then, after roscovitine removal, active MPF is already present and could induce meiotic resumption more rapidly than in untreated oocytes deprived of active MPF. Besides CDK inhibitors, protein synthesis (Mayes & Sirard, 2001) and phosphodiesterase inhibitors (Grupen et al, 2006), like IMBX, also accelerated meiotic resumption. Even short periods of meiotic block, as that used in the present study, cause such effects on nuclear maturation kinetics (Mayes & Sirard, 2001).…”

Application of In Vitro Maturation to Assisted Reproductive Technology

“…The effects of various kinase inhibitors on embryo development following IVM and IVF are summerized in Table 5. These studies show that controlling spontaneous meiotic progression by manupilating MPF activity, either adversely affects [58,68] or has no positive effect [59,60,77,78] on subsequent oocyte developmental competence after IVF except for our data (Fig. 7) [79].…”