Extrahypothalamic luteinizing hormone-releasing factor (LRF): release of immunoreactive LRF in vitro

The human placenta in vitro releases luteinizing hormone-releasing factor (LRF) which is immunologically indistinguishable from hypothalamic LRF. The release of LRF by placental tissue increased during the 4 days of culture and exceeded the original tissue content more than 5-fold. These data suggest that the human placenta may synthesize an LRF molecule immunologically identical with hypothalamic LRF.