Abamectin disrupts sperm function through the alteration of PKA activity and tyrosine phosphorylation in boar spermatozoa

The potential toxicity of abamectin (ABM), a macrocyclic lactone insecticide widely used in agriculture, in non-target organisms has raised concerns. Therefore, this study aimed to investigate the effects of ABM on sperm function, focusing on motility, kinematics, ATP levels, viability, protein kinase A (PKA) activity, and tyrosine phosphorylation. Boar spermatozoa were incubated with various ABM concentrations (0, 1, 5, 10, 15, 25, 50, and 100 µM) under capacitating conditions and assessed through computer-assisted sperm analysis, Hoechst 33258/chlortetracycline staining, ATP and viability assays, and Western blotting. The results revealed a dose-dependent decline in sperm motility and ATP levels starting at 10 µM. Sperm capacitation was significantly altered at concentrations of at least 25 µM, with an increase in capacitated spermatozoa and a decrease in non-capacitated spermatozoa. However, overall cell viability remained unaffected. Western blot analysis showed abnormal alterations in PKA substrates and tyrosine-phosphorylated proteins. These findings suggest ABM disrupts sperm function and key fertilization pathways, indicating potential risks to male fertility.