cosyntropin and Pleural-Effusion

A comparison has been made of the histamine-releasing characteristics of rat mast cells of pleural and peritoneal origin in response to a wide variety of immunological and non-immunological stimuli, namely, IgE antibody-antigen interaction; rabbit anti-rat antibody; concanvalin A (Con A); ACTH (1-24) polypeptide (Synacthen); a decapeptide comprising an amino acid sequence (497-506) within the human gamma-chain (Stanworth, Kings, Roy, Moran & Moran, 1979); adenosine triphosphate (ATP) and the calcium ionophore. This has provided valuable information about the relative responsiveness of target cells from two different sources within the same species. Pertioneal cells proved to be more responsive to basic polypeptide liberators, whereas pleural cells were considerably more responsive to stimuli mediated through IgE antibody, and slightly more responsive to challenge with non-immunological liberators. Interestingly, the histamine-release studies using an antiserum raised against mast cell IgE receptors have indicated that pleural mast cell membranes contain a higher density of IgE receptors than peritoneal mast cell membranes. Moreover, it was established that the amount of histamine release from either peritoneal or pleural mast cells effected by the polypeptide liberators was not influenced by the prior occupancy of the mast cell Fc receptors by rat IgE antibody.

Topics: Animals; Antigens; Ascitic Fluid; Calcium; Cosyntropin; Dose-Response Relationship, Drug; Dose-Response Relationship, Immunologic; Histamine Release; Immunization, Passive; Immunoglobulin E; Mast Cells; Peptides; Pleural Effusion; Rats; Receptors, Immunologic