Changes in spontaneous contractions of rat ileum by aflatoxin in vitro.
Aflatoxins are a group of mycotoxins produced by toxigenic strains of Aspergillusflavus, Aspergillusparasiticus and Aspergillusnomius as secondary metabolites. Most of the studies on the aflatoxins have focused mainly on their chronic toxic effects but aflatoxins have also a lot of acute effects on the respiratory, cardiovascular and gastrointestinal systems. In this study the acute gastrointestinal effects of the aflatoxins on rat isolated ileum and the possible mechanisms underlying contractile responses to them were investigated. Aflatoxin increased both of the amplitude and the frequency of spontaneous contractions in a dose-dependent manner. Pretreatment with a cholinergic system inhibitor, atropine sulfate (23.6nM), a specific sodium-channel blocker, tetrodotoxin (0.3microM) and an inhibitor of ACh release from terminal motor neurons, morphine (0.3microM) decreased both of aflatoxin induced spontaneous contractions' amplitude and frequency, in contrast a nicotinic ganglionic blocker, hexamethonium chloride (55microM) did not change the aflatoxin effect. But the decrease of amplitude was more than the frequency in the presence of these antagonists. In conclusion, these findings of aflatoxin on isolated rat ileum may explain their acute gastrointestinal effects in humans and animals.
Gursoy
Nevcihan
N
Faculty of Engineering, Department of Food Engineering, Cumhuriyet University, 58140 Sivas, Turkey. gursoy_gu@hotmail.com
Sarac
Bulent
B
Durmus
Nedim
N
Parlak
Ahmet
A
Yildirim
Sahin
S
Kaya
Tijen
T
Bagcivan
Ihsan
I
D000109:Acetylcholine / Q000378:metabolism; D000348:Aflatoxins / Q000494:pharmacology*; D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005769:Gastrointestinal Motility / Q000187:drug effects; D018738:Hexamethonium / Q000494:pharmacology; D007082:Ileum / Q000187:drug effects*; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000187:drug effects; D008297:Male; D009020:Morphine / Q000494:pharmacology; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009130:Muscle, Smooth / Q000187:drug effects*; D018733:Nicotinic Antagonists / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
D000348:Aflatoxins; D000701:Analgesics, Opioid; D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists; D026941:Sodium Channel Blockers; D018738:Hexamethonium; D013779:Tetrodotoxin; D009020:Morphine; D001285:Atropine; D000109:Acetylcholine