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

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) (pD(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.

Histopathological and ultrastructural assessment of two mugilid species infected with myxozoans and helminths

“…Both neutrophils and MCs have important role in intestine mucosal immunity and can co-occur in epithelium but most frequently in submucosal layer (Dezfuli et al, 2013(Dezfuli et al, , 2016, and the same finding was observed herein. MCs are present in many teleost species and are key regulatory cells active in coordination of many functions of the innate immunity (Dezfuli, Bo et al, 2015;Dezfuli et al, 2016;Secombes & Ellis, 2012 after inoculation of Aeromonas salmonicida exotoxins (Ellis, 1985;Vallejo & Ellis, 1989), although degranulation of MCs was induced ex vivo by use of compound 48/80 on intestinal tissue of rainbow trout (Manera, Giammarino, Borreca, Giari, & Dezfuli, 2011). In present survey, in L. saliens and L. ramada infected intestines, intense MCs degranulation was documented in close proximity to M. mugchelo plasmodia and its free mature spores.…”

“…Records on contents of granules of fish MCs revealed that they have a panel of inflammatory mediators (Da Silva et al., ; Dezfuli, Lui, Giovinazzo, Boldrini, & Giari, ; Galindo‐Villegas et al., ; Silphaduang & Noga, ). MCs degranulation was observed after inoculation of Aeromonas salmonicida exotoxins (Ellis, ; Vallejo & Ellis, ), although degranulation of MCs was induced ex vivo by use of compound 48/80 on intestinal tissue of rainbow trout (Manera, Giammarino, Borreca, Giari, & Dezfuli, ). In present survey, in L. saliens and L. ramada infected intestines, intense MCs degranulation was documented in close proximity to M. mugchelo plasmodia and its free mature spores.…”

Anguilla anguilla intestinal immune response to natural infection with Contracaecum rudolphii A larvae

“…Several investigations have demonstrated how MCs degranulate in response to exposure to a variety of known degranulating agents (Powell, Wright & Burka 1991;Manera et al 2011) and pathogens (Vallejo & Ellis 1989;Dezfuli et al 2008Dezfuli et al , 2013bpresent study) with the release of their contents. Mast cell products are pivotal in mediating leukocyte recruitment into inflammatory sites (Prykhozhi & Berman 2014).…”

“…Several investigations have demonstrated how MCs degranulate in response to exposure to a variety of known degranulating agents (Powell, Wright & Burka ; Manera et al . ) and pathogens (Vallejo & Ellis ; Dezfuli et al . , ; present study) with the release of their contents.…”

Proliferative cell nuclear antigen (PCNA) expression in the intestine of Salmo trutta trutta naturally infected with an acanthocephalan

“…In perciform fish, it has been reported that the mast cells contain histamine, which can regulate the fish’s inflammatory responses [42]. Moreover, MCs degranulation has been shown to promote intestinal contraction in Sparus aurata L. and in Oncorhynchus mykiss (Walbaum) [42,43]. …”