Leptin Modulates Behavioral Responses to Sweet Substances by Influencing Peripheral Taste Structures

Noriatsu Shigemura, Rie Ohta, Yuko Kusakabe, Hirohito Miura, Akihiro Hino, Kiyoshi Koyano, Kiyohito Nakashima, Yuzo Ninomiya

Research output: Contribution to journalArticle

140 Citations (Scopus)

Abstract

Leptin is a hormone that regulates body weight homeostasis mainly via the hypothalamic functional leptin receptor Ob-Rb. Recently, we proposed that the taste organ is a new peripheral target for leptin. Leptin selectively inhibits mouse taste cell responses to sweet substances and thereby may act as a sweet taste modulator. The present study further investigated leptin action on the taste system by examining expression of Ob-Rb in taste cells and behavioral responses to sweet substances in leptin-deficient ob/ob, and Ob-Rb-deficient db/db mice and their normal litter mates. RT-PCR analysis showed that Ob-Rb was expressed in taste cells in all strains tested. The db/db mice, however, had a RT-PCR product containing an abnormal db insertion that leads to an impaired shorter intracellular domain. In situ hybridization analysis showed that the hybridization signals for normal Ob-Rb mRNA were detected in taste cells in lean and ob/ob mice but not in db/db mice. Two different behavioral tests, one using sweet-bitter mixtures as taste stimuli and the other a conditioned taste aversion paradigm, demonstrated that responses to sucrose and saccharin were significantly decreased after ip injection of leptin in ob/ob and normal littermates, but not in db/db mice. These results suggest that leptin suppresses behavioral responses to sweet substances through its action on Ob-Rb in taste cells. Such taste modulation by leptin may be involved in regulation for food intake.

Original languageEnglish
Pages (from-to)839-847
Number of pages9
JournalEndocrinology
Volume145
Issue number2
DOIs
Publication statusPublished - Feb 1 2004

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All Science Journal Classification (ASJC) codes

  • Endocrinology

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