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Published on: September 27, 2017
Changes in spontaneous contractions of rat ileum by aflatoxin in vitro
Nevcihan Gursoy1, Bulent Sarac, Nedim Durmus
1Faculty of Engineering, Department of Food Engineering, Cumhuriyet University, 58140 Sivas, Turkey. gursoy_gu@hotmail.com
Abstract:
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.
Insights
Aflatoxins, toxic fungal metabolites, acutely increase contractions in rat ileum. This effect is mediated by the cholinergic system and sodium channels, not nicotinic ganglionic transmission, explaining gastrointestinal toxicity.
Area of Science:
- Toxicology
- Gastroenterology
- Pharmacology
Background:
- Aflatoxins are mycotoxins produced by Aspergillus species.
- Research has primarily focused on chronic aflatoxin toxicity.
- Acute effects on the respiratory, cardiovascular, and gastrointestinal systems are less understood.
Purpose of the Study:
- To investigate the acute gastrointestinal effects of aflatoxins on isolated rat ileum.
- To elucidate the mechanisms underlying aflatoxin-induced contractile responses.
Main Methods:
- Isolated rat ileum preparations were used.
- Dose-dependent contractile responses to aflatoxin were measured.
- The effects of cholinergic, sodium channel, and neuronal blockers (atropine sulfate, tetrodotoxin, morphine, hexamethonium chloride) were assessed.
Main Results:
- Aflatoxin significantly increased the amplitude and frequency of spontaneous ileum contractions in a dose-dependent manner.
- Atropine sulfate, tetrodotoxin, and morphine reduced both amplitude and frequency.
- Hexamethonium chloride did not alter aflatoxin's effect, indicating a post-ganglionic cholinergic mechanism.
Conclusions:
- Aflatoxins induce acute gastrointestinal effects via mechanisms involving the cholinergic system and sodium channels.
- These findings provide insight into the acute gastrointestinal toxicity of aflatoxins in humans and animals.
- The study highlights the role of neuronal pathways in mediating acute aflatoxin-induced gut responses.
