Direct modification of somatotrope function by long-term leptin treatment of primary cultured ovine pituitary cells

Sang Gun Roh, Gui Ying Nie, Kylie Loneragan, Arieh Gertler, Chen Chen

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)

Abstract

Leptin is produced primarily in adipocytes and regulates body energy balance. A close link between leptin and pituitary hormones, including GH, has been reported. The mechanisms employed by leptin to influence somatotropes are not clear, however. Here we report a direct action of recombinant ovine leptin on primary cultured ovine somatotropes by analyzing the levels of mRNA encoding for GH or the receptors for GHRH (GHRH-R) and GH-releasing peptides (GHRP). Treatment of ovine somatotropes with leptin (10-7-10-9M) for 1-3 d reduced the mRNA levels encoding GH and GHRH-R, but increased GHRP receptor mRNA levels in a time- and dose-dependent manner. Three-day treatment of cells with leptin decreased the GH response to GHRH stimulation, but the GH response to GHRP-2 stimulation was increased. The combined effect of GHRH and GHRP-2 on GH secretion was not altered by treatment of the cells with leptin. These results demonstrated a direct action of leptin on ovine pituitary cells, leading to a reduced sensitivity of somatotropes to GHRH. It is also suggested that GHRP may be useful to correct the decrease in GHRH-induced GH secretion by leptin.

Original languageEnglish
Pages (from-to)5167-5171
Number of pages5
JournalEndocrinology
Volume142
Issue number12
DOIs
Publication statusPublished - 2001
Externally publishedYes

ASJC Scopus subject areas

  • Endocrinology

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