<prompt> Mast cells secrete all except:HistamineHeparinMIPBradykinin  <response>: Ans: d Bradykinin When presensitized mast cells bind to new antigens two parallel and independent processes take place:1 Degranulation of preformed primary mediatorsi Biogenic amines - Histamineii Enzymes - neutral proteases chymase, tryptase acid hydrolasesiii Proteoglycans - Heparin, Chondroitin sulfate2 Synthesis and release of secondary mediatorsi Lipid mediators - Leukotriene C4 D4Prostaglandins D2Most abundantPAFii Cytokines - IL1 , IL3, IL4, IL5, IL6,TNF, GMCSF,MIP 1 alpha, MIP 1 beta 