Abstract
Long-term exposure of tilapia to p-nonylphenol (NP) or estradiol-17 beta (E) resulted in a decrease in FSH beta mRNA levels. LH beta mRNA was less affected. Short-term direct treatment of pituitary cells to these compounds had a stimulatory effect on GtH (possibly LH) secretion. E injection elevated the mRNA of GnRH receptor (GnRH-R) in a dose-dependent manner.