Immunoreactive GnRH suggesting a third form of GnRH in addition to cIIGnRH and sGnRH in the brain and pituitary gland of Prochilodus lineatus (Characiformes).

Molecular variants of GnRH (gonadotropin-releasing hormone) in brain and pituitary extracts of the South American characiforme Prochilodus lineatus were studied using a combination of reverse-phase high-performance liquid chromatography and radioimmunoassay with different antisera. In brain extracts our study revealed that this fish has at least two different types of GnRH: cIIGnRH (chicken II) and sGnRH (salmon), and possibly a third variant of this molecule. In pituitary extracts we could find only two immunoreactive peaks corresponding to sGnRH and the possible third form.