Short-chain fatty acids stimulate colonic transit via intraluminal 5-HT release in rats.
We studied whether physiological concentration of short-chain fatty acids (SCFAs) affects colonic transit and colonic motility in conscious rats. Intraluminal administration of SCFAs (100-200 mM) into the proximal colon significantly accelerated colonic transit. The stimulatory effect of SCFAs on colonic transit was abolished by perivagal capsaicin treatment, atropine, hexamethonium, and vagotomy, but not by guanethidine. The stimulatory effect of SCFAs on colonic transit was also abolished by intraluminal pretreatment with lidocaine and a 5-hydroxytryptamine (HT)(3) receptor antagonist. Intraluminal administration of SCFAs provoked contractions at the proximal colon, which migrated to the mid- and distal colon. SCFAs caused a significant increase in the luminal concentration of 5-HT of the vascularly isolated and luminally perfused rat colon ex vivo. It is suggested that the release of 5-HT from enterochromaffin cells in response to SCFAs stimulates 5-HT(3) receptors located on the vagal sensory fibers. The sensory information is transferred to the vagal efferent and stimulates the release of acetylcholine from the colonic myenteric plexus, resulting in muscle contraction.
Fukumoto
Satoshi
S
Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
Tatewaki
Makoto
M
Yamada
Tadanori
T
Fujimiya
Mineko
M
Mantyh
Chris
C
Voss
Miranda
M
Eubanks
Steve
S
Harris
Mary
M
Pappas
Theodore N
TN
Takahashi
Toku
T
D000818:Animals; D003106:Colon / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D005232:Fatty Acids, Volatile / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D005243:Feces; D005769:Gastrointestinal Motility / Q000187:drug effects*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism* / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology
D005232:Fatty Acids, Volatile; D012702:Serotonin Antagonists; D012701:Serotonin