Release of slow-reacting substance of anaphylaxis and leukotriene C4-like immunoreactivity from guinea pig colonic tissue.
Colonic mucosa, muscularis propria and subserosa from ovalbumin-sensitized guinea pigs were incubated and challenged with antigen in vitro. Slow-reacting substance of anaphylaxis (SRS-A) was determined biologically as well as radioimmunologically in terms of leukotriene (LT) C4-like immunoreactivity. Before antigenic challenge release of immunoreactive LTC4 by all tissues was below or close to the detection limit of the radioimmunoassay. After addition of antigen colonic mucosa released considerable amounts of LTC4-like immunoreactivity, while muscularis propria and subserosa were less active. The biological activity of the SRS-A formed after challenge was antagonized by FPL 55712. Contrary to LTC4-like immunoreactivity release of 6-keto-prostaglandin (PG) F1 alpha was predominant in the subserosa and smaller amounts were released from the smooth muscular and mucosal layers. Synthesis of SRS-A and LTC4-like immunoreactivity, respectively, as well as synthesis of 6-keto-PGF1 alpha was inhibited by the dual inhibitor of lipoxygenase and cyclooxygenase BW755c. The results suggest a role for LTs as local mediators of inflammatory reactions in colonic disease states, particularly those with possible involvement of immunological processes.
D015772:4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine; D015121:6-Ketoprostaglandin F1 alpha / Q000378:metabolism; D000818:Animals; D003106:Colon / Q000378:metabolism*; D006168:Guinea Pigs; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism; D010047:Ovalbumin / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D011863:Radioimmunoassay; D013189:SRS-A / Q000378:metabolism*
D011720:Pyrazoles; D013189:SRS-A; D015121:6-Ketoprostaglandin F1 alpha; D015772:4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyrazol-3-amine; D010047:Ovalbumin