Stimulation of Cl^- Secretion by L-Alanine Oligopeptides in the Mammalian Large Intestine

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Author(s)

Abstract

A variety of oligopeptides are probably released within the intestinal tissue under inflammatory conditions or during peptide absorption. To examine whether some of these peptides can affect intestinal transport functions, we determined the effects of l-alanine oligopeptide on short-circuit current (I<sub>sc</sub>) and transmucosal conductance (G<sub>t</sub>) in submucosa-mucosa preparations from the mouse cecum and guinea pig distal colon in vitro in Ussing chambers. l-Alanyl-l-alanine (Ala-Ala, 10 mm) added to the serosal side increased I<sub>sc</sub> and G<sub>t</sub>, giving a peak followed by a sustained phase (the peak increase in I<sub>sc</sub> was 45 ± 6 μA/cm<sup>2</sup> and the increase in G<sub>t</sub> was 0.55 ± 0.11 mS/cm<sup>2</sup>). The tripeptide, l-alanyl-l-alanyl-l-alanine (Ala-Ala-Ala, 10 mm), added to the serosal side also induced increases in I<sub>sc</sub> and G<sub>t</sub> by a similar degree. On the other hand, luminal Ala-Ala, and serosal l-alanine and d-alanine (10 mm) caused significantly smaller increases in I<sub>sc</sub> and G<sub>t</sub> (~15 μA/cm<sup>2</sup> and ~0.15 mS/cm<sup>2</sup>, respectively). The Ala-Ala induced increase in I<sub>sc</sub> was partially inhibited by serosal bumetanide (0.1 mm) and mucosal 5-nitro-2-(3-phenylpropylamino)benzoic acid (0.1 mm), and largely suppressed by removing Cl<sup>−</sup> from the bathing solution. The increase in I<sub>sc</sub> was largely suppressed by serosal low Ca<sup>2+</sup> and tetrodotoxin, but was not affected by indomethacin. In the guinea pig distal colon, serosal Ala-Ala (10 mm) evoked a transient increase in I<sub>sc</sub> by 23 ± 7 μA/cm<sup>2</sup> and an increase in G<sub>t</sub> by 1.2 ± 0.3 mS/cm<sup>2</sup>. These results suggest that Ala-Ala, and probably also Ala-Ala-Ala, added to the serosal side stimulated electrogenic Cl<sup>−</sup> secretion mainly through the activation of submucosal secretomotor neurons in the mammalian large intestine. <br>

Journal

  • The Japanese Journal of Physiology

    The Japanese Journal of Physiology 50(3), 323-328, 2000-06

    THE PHYSIOLOGICAL SOCIETY OF JAPAN

References:  17

Codes

  • NII Article ID (NAID)
    10008291492
  • NII NACSIS-CAT ID (NCID)
    AA00691224
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    0021521X
  • NDL Article ID
    5525756
  • NDL Source Classification
    ZS8(科学技術--医学--解剖学・生理学・生化学)
  • NDL Call No.
    Z53-D40
  • Data Source
    CJP  NDL  J-STAGE 
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