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Motility changes induced by intraluminal FeSO 4 in guinea pig jejunum
Author(s) -
Wang K.,
Bertrand R. L.,
Senadheera S.,
Polglaze K. E.,
Murphy T. V.,
Sandow S. L.,
Liu L.,
Bornstein J. C.,
Bertrand P. P.
Publication year - 2014
Publication title -
neurogastroenterology and motility
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.489
H-Index - 105
eISSN - 1365-2982
pISSN - 1350-1925
DOI - 10.1111/nmo.12276
Subject(s) - decanoic acid , jejunum , motility , chemistry , peristalsis , medicine , endocrinology , biochemistry , biology , genetics
Background Dietary iron supplementation is associated with gastrointestinal ( GI ) side effects including vomiting, nausea, and diarrhea. Although inorganic iron in high concentrations may be damaging to the intestinal mucosa, we hypothesize that there are physiological effects on the GI tract that occur at concentrations achieved by supplementation. Thus, our aim was to investigate the effect of intraluminal ferrous sulfate ( FeSO 4 ) on jejunal motility. Methods Segments of guinea pig jejunum were cannulated and the intraluminal pressure recorded with a transducer, while movements were recorded with a video camera. Peristaltic threshold was the oral pressure that evoked four consecutive propulsive contractions. The nutrients decanoic acid (1 mM), l ‐phenylalanine (50 mM), or the micronutrient FeSO 4 (1 mM) were infused intraluminally. We also tested the effect of FeSO 4 on electrochemically detected serotonin (5‐ HT , 5‐hydroxytryptamine) released from in vitro tissues, both at rest and following mechanical stimulation. Key Results The jejuna peristaltic threshold was significantly decreased by all three nutrients: FeSO 4 : 31 ± 2–23 ± 3 mm H 2 O ; decanoic acid: 27 ± 2–14 ± 2 mm H 2 O ; and l ‐phenylalanine: 30 ± 3–14 ± 3mm H 2 O . Of the three, only decanoic acid induced segmentation, while FeSO 4 inhibited decanoic acid‐induced segmentation. Resting 5‐ HT release was increased by FeSO 4 (128% of control), but mechanically evoked 5‐ HT release was reduced (70% of control). Conclusions & Inferences These data suggest that some luminal effects of inorganic iron on jejunal motility could be mediated through a pathway involving altered release of 5‐ HT . A better understanding of the interaction between luminal iron and 5‐ HT containing enterochromaffin cells could improve iron supplementation strategies, thus reducing side effects.