Degranulation of mast cells due to compound 48/80 induces concentration-dependent intestinal contraction in rainbow trout (Oncorhynchus mykiss Walbaum) ex vivo

✍ Scribed by M. Manera; A. Giammarino; C. Borreca; L. Giari; B.S. Dezfuli

• Publisher: Wiley (John Wiley & Sons)
• Year: 2011
• Tongue: English
• Weight: 388 KB
• Volume: 315A
• Category: Article
• ISSN: 1932-5223
• DOI: 10.1002/jez.692

✦ Synopsis

Abstract

Rainbow trout (Oncorhynchus mykiss) intestinal strips (n = 10) were mounted in an isolated organ bath and the effect of incremental doses of compound 48/80 was recorded. Compound 48/80 induced concentration‐related contraction in all the examined strips following a sigmoidal dose–response curve fit. Values for maximal contraction (E~max~, g cm^−2^), negative logarithm of the EC~50~ (p__D__~2~), and hill slope were, respectively (mean±standard error), 12.88 ± 0.51, 1.88 ± 0.05, 1.49 ± 0.27. The histological modification induced on mast cells (MCs) due to compound 48/80 was characterized by mean of gray‐levels and texture analysis. Significant differences were observed between gray‐levels values (Linear mixed model, P<0.01), contrast, and entropy (Linear mixed model, P<0.05) of MCs from compound 48/80‐treated strips compared with MCs from untreated strips. Moreover, maximal intestinal contraction (due to compound 48/80) correlates positively and significantly (Pearson and Spearman correlations, P<0.05) with degranulation intensity determined by means of gray‐levels analysis. Four antisera were tested on intestinal sections and no MCs positive to serotonin, substance P, met‐enkephalin, and bombesin were found. This study demonstrates that compound 48/80 induces the degranulation of trout intestinal MCs ex vivo, and that the aforementioned degranulation promotes a concentration‐dependent intestinal contraction. J. Exp. Zool. 315:447–457, 2011. © 2011 Wiley‐Liss, Inc.