The LH RH and FSH RH activities of the synthetic LH RH decapeptides [Des Gly10] [Pro9 ethylamide] LH RH (EA LH RH) and [Des Gly10] [Pro9 propylamide] LH RH (PA LH RH) were evaluated using immature male rats. A sc injection of 70 ng or 100 ng of EA LH RH induced a greater rise in serum LH and FSH levels than did these doses of LH RH, but the pattern of changes in serum LH and FSH levels was similar. Elevation of serum LH and FSH levels after injection of 100 ng of PA LH RH was more prolonged than after the same dose of EA LH RH or LH RH. The highest levels of LH were observed after EA LH RH. Peak FSH levels in response to EA LH RH and PA LH RH were similar and considerably higher than those after LH RH. The integrated amounts of LH released after 100 ng of EA LH RH and PA LH RH were similar and approximately 5.5 times greater than those after 100 ng of LH RH. The integrated amounts of FSH released after 100 ng of EA LH RH and PA LH RH were approximately 7 and 9.4 times greater than those after LH RH, respectively. Thus, EA LH RH and PA LH RH have been shown to release more gonadotropins than does LH RH, and, in addition, administration of PA LH RH exhibits a more prolonged effect.
|Original language||English (US)|
|Number of pages||4|
|Journal||Proceedings of the Society for Experimental Biology and Medicine|
|State||Published - May 1974|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)