Downregulation of leptin by free fatty acids in rat adipocytes: Effects of triacsin C, palmitate, and 2-bromopalmitate

Mitsuyo Shintani, Haruo Nishimura, Shin Yonemitsu, Hiroaki Masuzaki, Yoshihiro Ogawa, Kiminori Hosoda, Gen Inoue, Yasunao Yoshimasa, Kazuwa Nakao

Research output: Contribution to journalArticlepeer-review

55 Citations (Scopus)

Abstract

Free fatty acid (FFA) has been reported to decrease leptin mRNA levels in 3T3-L1 adipocytes. When using this cell line, it is difficult to determine the protein levels because a very small amount of leptin is secreted into the medium. The effect of FFA on leptin secretion from adipocytes has not yet been determined. In addition, in vivo studies have failed to demonstrate a FFA-induced decrease in plasma leptin levels. To clarify the effect of FFA on leptin production, we investigated the leptin protein level in the medium and the mRNA level in primary cultured rat adipocytes treated with triacsin C, which is a potent inhibitor of acyl-coenzyme A (CoA) synthetase, palmitate, and 2-bromopalmitate. Triacsin C (0 to 5 x 10-5 mol/L) decreased leptin concentrations in the culture medium in a close-dependent manner. Leptin mRNA levels were decreased to 10% of the control in the presence of triacsin C. The concentration of triacsin C needed to suppress leptin production was similar to the K(i) value (≃ 10-5 mol/L) for inhibition of acyl-CoA synthetase. Both palmitate and 2-bromopalmitate decreased leptin concentrations but did not affect the triacsin C-induced decrease in leptin additively. In conclusion, both protein and mRNA levels of leptin were decreased by triacsin C and FFA in primary cultured rat adipocytes. Our findings suggest that FFA is involved in the regulation of leptin production in adipocytes. (C) 2000 by W.B. Saunders Company.

Original languageEnglish
Pages (from-to)326-330
Number of pages5
JournalMetabolism: Clinical and Experimental
Volume49
Issue number3
DOIs
Publication statusPublished - Jan 1 2000
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology

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