Anandamide acts via kisspeptin in the regulation of testicular activity of the frog, Pelophylax esculentus

Schematic model of AEA activity along the HPG axis. Injection of AEA in male frogs down-regulates the HPG axis targeting kisspeptin/Gnrh systems in the hypothalamus and up-regulates Cyp19 in testis. As a consequence, intratesticular testosterone levels are low whereas estrogen biosynthesis increases and negative feedback mechanisms occur in both hypothalamus and pituitary. In testis high estrogen levels induce Faah protein production; AEA increases Cyp19 expression and thus, via estradiol, modulates its tone.109