Testicular Steroidogenesis and Locomotor Activity Are Regulated by Gonadotropin-Inhibitory Hormone in Male European Sea Bass

Abstract

In this study, we performed periodic implants of GnIH (sbGnIH1, sbGnIH2) during the late stages of the reproductive cycle and confirmed the inhibitory effects of GnIH on European sea bass reproduction. The results showed that GnIH reduced androgen secretion, inhibited testicular development, and decreased gonadotropin synthesis and secretion, particularly Lh. Additionally, the study highlighted the inhibitory effects on the nocturnal reproductive behavior characteristic of this species. These findings demonstrated the regulatory role of GnIH in the reproductive axis by modulating brain and pituitary hormones as well as gonadal physiology and reproductive behavior.