Non-pungent capsaicin analogs (capsinoids) increase metabolic rate and enhance thermogenesis via gastrointestinal TRPV1 in mice.
Capsinoids are non-pungent capsaicin analogs which increase energy expenditure like capsaicin. However, the mechanisms underlying the enhancement of their energy expenditure despite their non-pungency are poorly understood. We suggest here that capsinoids increase energy expenditure in wild-type mice, but not in transient receptor potential vanilloid 1 (TRPV1) knockout mice, implying that capsinoids increase energy expenditure via TRPV1. The jejunal administration of capsinoids to anesthetized mice raised the temperature of the colon and intrascapular brown adipose tissue. Denervation of the extrinsic nerves connected to the jejunum inhibited this temperature elevation. These findings suggest that capsinoids increase energy expenditure by activating the intestinal extrinsic nerves. Although the jejunal administration of capsinoids did not raise the tail skin temperature, an intravenous injection of capsinoids did, indicating that capsinoids could barely pass through the intestinal wall into the blood. Taken together, gastrointestinal TRPV1 may be a critical target for capsinoids to enhance energy expenditure.
Kawabata
Fuminori
F
Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Japan. carl419tri@yahoo.co.jp
Inoue
Naohiko
N
Masamoto
Yukiko
Y
Matsumura
Shigenobu
S
Kimura
Wakako
W
Kadowaki
Makoto
M
Higashi
Tomohiro
T
Tominaga
Makoto
M
Inoue
Kazuo
K
Fushiki
Tohru
T
D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D002211:Capsaicin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*; D003714:Denervation; D004734:Energy Metabolism / Q000187:drug effects; D005740:Gases / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000187:drug effects* / Q000294:innervation / Q000378:metabolism* / Q000502:physiology; D055786:Gene Knockout Techniques; D007275:Injections, Intravenous; D007583:Jejunum / Q000187:drug effects / Q000294:innervation / Q000378:metabolism / Q000502:physiology; D007700:Kinetics; D008297:Male; D051379:Mice; D010084:Oxidation-Reduction; D012119:Respiration / Q000187:drug effects; D012867:Skin / Q000187:drug effects; D050916:TRPV Cation Channels / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D022722:Thermogenesis / Q000187:drug effects*
D005740:Gases; D050916:TRPV Cation Channels; C493921:TRPV1 protein, mouse; D002211:Capsaicin