Role of Prostaglandins in Fish Reproduction

Publisher Website
Google Scholar
Abstract
Prostaglandins (PGs) have been identified in gonads, semen, ovarian fluid, blood, and in vitro ovarian incubates from a variety of teleosts. In teleosts, PGs appear to be involved in ovulation (follicular rupture) and female sexual behavior, and possibly in gonadotropin (GtH) secretion. An increase in prostaglandin F (PGF) levels associated with GtH-induced ovulation occurs in vivo in the pond loach (Misgurnus anguillicaudatus) and goldfish (Carassius auratus). Indomethacin (PG synthesis inhibitor) blocks ovulation in these species and, in goldfish, PG injection reverses this blockade. PGF2α stimulates in vitro ovulation in rainbow trout (Salmo gairdneri), brook trout (Salvelinus fontinalis), and yellow perch (Perca flavescens); however, in perch, PGE2 is the most potent prostaglandin. Addition of melatonin to incubation medium both inhibits ovulation and decreases PGE and PGF synthesis in yellow perch, while addition of epinephrine and theophylline both enhances ovulation and increases PGE and PGF synthesis. Several studies indicate that PG, released from the ovaries or oviduct in response to the presence of ovulated oocytes, acts on the brain to stimulate female spawning behavior in the goldfish. Other externally fertilizing teleosts may use similar mechanisms to synchronize female sexual behavior with ovulation.Key words: prostaglandins, fish reproduction, ovulation, sexual behavior