Effect of the addition of different concentrations of L-carnitine during porcine in vitro maturation on embryo quality and development

CRUZANS, PR.; LORENZO, MS.; TEPLITZ, G.; LUCHETTI, CG.; LOMBARDO, DM.

Bologna

Congreso; 19th International Congress on Animal Reproduction; 2020

ICAR Committee

L-carnitine (LC) plays an important role in the catabolism of lipids and protects cells from the damage caused by reactive oxygen species due to its antioxidant activity. The aim of this study was to evaluate the effect of the addition of different concentrations of LC during porcine in vitro maturation on embryo quality and development. The cumulus-oocyte complexes were obtained by follicular aspiration from ovaries of slaughtered sows and matured in vitro for 44 h without LC (control) or with different concentrations of LC (0.6 or 1.25 mg/mL) (Sigma-Aldrich) in TCM-199 supplemented with human menopausal gonadotrophin and dAMPc during the first 22 h. In vitro fertilization was performed with fresh boar semen for 4 h in 100 µL- drop of TCM 199 with caffeine, BSA, sodium lactate, and pyruvate (20 denuded oocytes per drop, 1x106 spermatozoa/mL). Presumptive zygotes were washed and cultured in NCSU 23 at 39°C, 7 % O2, 5 % CO2, and humidity. The cleavage rate was registered on day 2 and the blastocyst rate on day 7. Embryo quality was assessed by counting the number of cells per blastocyst (Hoescht 33342) and late apoptosis index (TUNEL positive cells/total cells). TUNEL was performed according to the kit protocol (Roche). LC significantly decreased the cleavage rate (control: 46.2%; LC 0.6: 32.1%; LC 1.25: 37.9%; p < 0.05, Chi-square test). No significant differences were detected in the blastocyst rate (control: 19.2%; LC 0.6: 17%; LC 1.25: 10,2%, Chi-square test) and in the number of cell per blastocyst (control: 51.97±3; LC 0.6: 56.11±4; LC 1.25: 45.62±4, ANOVA). There was embryo hatching in LC treatments but not in the control (control: 0%, LC 0.6: 11%; LC 1.25: 7.6%). The apoptosis index decreased in LC 1.25 in compare to LC 0.6 (Control: 7,6±1.3%; LC 0.6: 10±1.1%; LC 1.25: 5,5±0.8%; p < 0.05, ANOVA) but there was no significant difference in the apoptosis index between control and LC treatments. In conclusion, LC treatments decreased the cleavage rate but did not modify the blastocyst rate, and allows embryo hatching.