A cryptic peptide (160—169) of thyrotropin-releasing hormone prohormone demonstrates biological activity in vivo and in vitro

Frances E. Carr, Henry G. Fein, Carolyn U. Fisher, Martin W. Wessendorf, Robert C. Smallridge

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

TRH is synthesized as a precursor peptide containing five copies of the sequence Gln-His-Pro-Gly, QHPG, flanked by paired basic amino acids, and linked by other peptides. We tested one cryptic peptide, PPT (160-169, SFPWMESDVT), as a possible physiological regulator of pituitary activity in vivo. Male rats were cannulated (jugular) and received a single dose of either PPT or TRH (10-8-10-6M). PPT caused no consistent effects on either TSH or PRL secretion, while TRH stimulated the secretion of both hormones. However, PPT stimulated a dose-dependent increase in both pituitary TSHβ and PRL mRNA content at 240 min similar to TRH. In primary cultures of rat pituitar-ies, PPT stimulated a maximum 4-fold increase in TSHβ mRNA and a 2-fold increase in PRL mRNA in 4 h, while TRH increased both TSHβ and PRL mRNA approximately 3-fold. Again, PPT had no significant effect on TSH or PRL secretion into the medium. Thus, PPT appears to be a physiological regulator of both TSH and PRL synthesis, but, unlike TRH, does not act as a secretagogue.

Original languageEnglish (US)
Pages (from-to)2653-2658
Number of pages6
JournalEndocrinology
Volume131
Issue number6
DOIs
StatePublished - Dec 1992

ASJC Scopus subject areas

  • Endocrinology

Fingerprint Dive into the research topics of 'A cryptic peptide (160—169) of thyrotropin-releasing hormone prohormone demonstrates biological activity in vivo and in vitro'. Together they form a unique fingerprint.

  • Cite this