Vasoactive intestinal peptide null mice demonstrate enhanced sweet taste preference, dysglycemia and reduced taste bud leptin receptor expression

  1. Bronwen Martin1,
  2. Yu-Kyong Shin1,
  3. Caitlin M. White1,
  4. Sunggoan Ji1,
  5. Wook Kim1,
  6. Olga D. Carlson1,
  7. Joshua K. Napora1,
  8. Wayne Chadwick1,
  9. Megan Chapter1,
  10. James A. Waschek2,
  11. Mark P. Mattson1,
  12. Stuart Maudsley1 and
  13. Josephine M. Egan (eganj{at}mail.nih.gov)1
  1. 1National Institute on Aging/NIH, 251 Bayview Blvd., Suite 100, Baltimore, MD 21224, USA
  2. 2Semel Institute for Neuroscience, Mental Retardation Research Center, Department of Psychiatry and Behavioral Sciences, University of California, Los Angeles

Abstract

Objective – It is becoming apparent that there is a strong link between taste perception and energy homeostasis. Recent evidence implicates gut-related hormones in taste perception, including glucagon-like peptide 1 and vasoactive intestinal peptide (VIP). We employed VIP knock-out (KO) mice to investigate VIP's specific role in taste perception and connection to energy regulation.

Research Design And Methods – Bodyweight, food intake and plasma levels of multiple energy regulating hormones were measured and pancreatic morphology was determined. Additionally, the immunocytochemical profile of taste cells (TCs) and gustatory behavior was examined in wild-type and VIP KO mice.

Results – VIP KO mice demonstrate elevated plasma glucose, insulin and leptin levels, with no islet beta-cell number/topography alteration. VIP and its receptors (VPAC1, VPAC2) were identified in Type II TCs of the taste bud, and VIP KO mice exhibit enhanced taste preference to sweet tastants. VIP KO mice TCs show a significant decrease in leptin receptor expression and elevated expression of glucagon-like peptide 1, which may explain VIP KO mice sweet taste preference.

Conclusions – This suggests that the tongue can play a direct role in modulating energy intake to correct peripheral glycemic imbalances. In this way, we could view the tongue as a sensory mechanism that is bi-directionally regulated, and thus forms a bridge between available foodstuffs and the intricate hormonal balance in the animal itself.

Footnotes

    • Received June 10, 2009.
    • Accepted January 28, 2010.

This Article

  1. Diabetes
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