[Factor from rat and bovine pineal organs immunologically and biologically related to luliberin].

Luteinizing hormone releasing hormone (LH-RH, luliberin) was revealed in the pineal organs of rats and cattle. The luliberin content per organ varied in rats from 5 to 66 ng, depending on sex and age. In some cases it could not be revealed by the direct radioimmunological method in the organ extracts, while neurohormone was detected by chromatography on carboxymethylcellulose or on Sephadex G-15. About 0.5 ng of LH-RH is contained in the bocine pineal organs, and the neurohormone competed with 125I-LH-RH for binding with a specific antiserum in the same way as synthetic luliberin. Mobility of LH-RH from the bovine and rat pineal organs during carboxymethylcellulose chromatography in the column coincided with such for synthetic LH-RH and the neurohormone from the rat hypothalamus. Besides, luliberin from the bovine pineal glands injected intraperitoneally to rats led to elevation of the LH blood level. No such effect occurred when luliberin from the epiphyses was preliminarily incubated with the LH-RH antiserum. A possible role played by luliberin in the pineal organ is discussed.