Paradoxical effects of D-TRP416-LHRH in immature female rats correlated with changes in ACTH, prolactin, and corticosterone levels

M. V. Nekola, E. Pedroza, A. V. Schally

Research output: Contribution to journalArticle

3 Scopus citations


Immature female rats were treated with D-Trp6-LHRH to determine if the delay in vaginal opening induced by the superactive agonist of LHRH could be correlated with changes in ACTH, prolactin, or corticosterone levels. The rats were injected daily from Day 30 to Day 40 of age with 0.05 or 1 μg of D-Trp6-LHRH or with saline alonge. Six animals per group were sacrificed on Days 31, 35, 38, or 42 and trunk blood collected. Pituitary and adrenal weights did not vary between groups, but increased in all treatment regimens as the animals grew older. Prolactin and ACTH levels increased on Days 35 and 38 in the control animals, but were significantly reduced in both agonist-treated groups. Relative to controls, serum corticosterone was elevated (P<0.05) on Day 31 in 0.05 μg-treated animals and decreased on Day 38 in animals treated with 1 μg D-Trp6-LHRH. The addition of corticosterone (160 μg/ml in 4% ethanol) to the drinking water reversed the inhibitory effects of 1 μg of D-Trp6-LHRH on vaginal opening. In animals treated with saline or 0.05 μg D-Trp6-LHRH, corticosterone did not affect the normal vaginal opening. These results demonstrate that it is possible that D-Trp6-LHRH delays vaginal opening through its effects on corticosterone levels.

Original languageEnglish (US)
Pages (from-to)505-511
Number of pages7
JournalBiology of Reproduction
Issue number3
StatePublished - Jan 1 1981
Externally publishedYes


ASJC Scopus subject areas

  • Reproductive Medicine
  • Cell Biology

Cite this