Propionate modulates spontaneous contractions via enteric nerves and prostaglandin release in the rat distal colon.
Short-chain fatty acids, such as propionate and acetate, are produced by a bacterial fermentation of carbohydrates in the colonic lumen. We examined the effects of propionate on the frequency and mean amplitude of spontaneous giant contractions (GCs) in circular muscle strips of the rat distal colon with the mucosa attached. An addition of propionate increased the frequency of GCs for about 20 min (> or =1 mm), but the mean amplitude was decreased (> or =0.1 mm). The propionate-induced increase in the frequency of GCs was blocked by the muscarinic acetylcholine receptor antagonist, atropine. In contrast, the nicotinic receptor antagonist, hexamethonium, augmented the response. The propionate-induced decrease in the mean amplitude of GCs was prevented by the cyclooxygenase inhibitor, piroxicam. A pretreatment of the tissues with acetate prevented the propionate-induced modulations of the frequency and amplitude of GCs. These results suggest that propionate increases the frequency of GCs by an activation of cholinergic motor neurons and decreases the mean amplitude by a prostaglandin release. Propionate as well as acetate may be involved in the regulation of spontaneous circular muscle activity in the rat distal colon.
Mitsui
Retsu
R
Laboratory of Physiology, Graduate School of Nutritional and Environmental Sciences, Institute for Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan.
Ono
Shigeyuki
S
Karaki
Shin-ichiro
S
Kuwahara
Atsukazu
A
D000085:Acetates / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002799:Cholinergic Fibers / Q000187:drug effects / Q000502:physiology; D044683:Colon, Descending / Q000294:innervation / Q000378:metabolism*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D017615:Enteric Nervous System / Q000502:physiology*; D005769:Gastrointestinal Motility / Q000187:drug effects / Q000502:physiology; D017829:Granisetron / Q000494:pharmacology; D018738:Hexamethonium / Q000494:pharmacology; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects / Q000294:innervation* / Q000502:physiology*; D018733:Nicotinic Antagonists / Q000494:pharmacology; D010894:Piroxicam / Q000494:pharmacology; D011422:Propionates / Q000494:pharmacology*; D011453:Prostaglandins / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012702:Serotonin Antagonists / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
D000085:Acetates; D001285:Atropine; D016861:Cyclooxygenase Inhibitors; D017829:Granisetron; D018738:Hexamethonium; D007650:Ketanserin; D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists; D010894:Piroxicam; D011422:Propionates; D011453:Prostaglandins; D012702:Serotonin Antagonists; D013779:Tetrodotoxin