Pilot studies to demonstrate that intestinal mucosal afferent nerves are functionally linked to visceral adipose tissue.
Dietary capsaicin reduces rodent visceral fat weight. We tested the hypothesis that intact intestinal mucosal afferent nerve function is necessary for fat deposition in visceral adipose tissue sites. Rats were treated daily for 2 weeks with intragastric (chronic treatment) vehicle or capsaicin. Superior mesenteric artery blood flow and mesenteric and inguinal fat blood flow were measured before and after capsaicin was administered into the duodenum (acute treatment). Fat from all sites was dissected and weighed. Chronic capsaicin significantly attenuated acute capsaicin-induced mesenteric hyperemia but did not abolish the reflex wiping of the eye exposed to capsaicin, indicating that functional ablation was limited to the intestinal mucosal afferent nerves. The associated vasoconstriction in adipose tissue was inhibited at the visceral (mesenteric) site and maintained but attenuated at the subcutaneous (inguinal) site. The onset of vasoconstriction was instantaneous, indicating a reflex mechanism. There was a redistribution of fat from visceral to subcutaneous sites, reflected by a decrease and an increase in the percentage of body fat in the visceral and subcutaneous sites, respectively. These pilot studies reveal for the first time that normal intestinal mucosal afferent nerve function is necessary for the physiologic accumulation of fat in visceral adipose tissue sites.
Leung
Felix W
FW
Research and Medical Services, Sepulveda Ambulatory Care Center and Nursing Home, Sepulveda, California 91343, USA.
Go
Vay Liang W
VL
Scremin
Oscar U
OU
Obenaus
Andre
A
Tuck
Michael L
ML
Golub
Michael S
MS
Eggena
Peter
P
Leung
Joseph W
JW
D000273:Adipose Tissue / Q000098:blood supply / Q000502:physiology*; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage; D000818:Animals; D001783:Blood Flow Velocity; D001835:Body Weight; D002211:Capsaicin / Q000008:administration & dosage; D004195:Disease Models, Animal; D004333:Drug Administration Routes; D004386:Duodenum; D007413:Intestinal Mucosa / Q000187:drug effects / Q000294:innervation*; D017078:Laser-Doppler Flowmetry; D017538:Mesenteric Artery, Superior / Q000187:drug effects / Q000502:physiology; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology*; D009765:Obesity / Q000209:etiology / Q000503:physiopathology; D010865:Pilot Projects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014781:Viscera
D018712:Analgesics, Non-Narcotic; D002211:Capsaicin