title: Computerization of a bioassay: quantitation of slow reacting substance of anaphylaxis (SRS-A).
abstract: The bioassay for SRS-A using isolated guinea-pig ileum bathed in atropine and pyrilamine has been computerized resulting in a more accurate collection and calculation of data. Areas under the polygraph tracings are calculated by a computer interfaced with the recording polygraph. After comparison of ileal responses obtained with known amounts of SRS-A standard, the computer determined the relative amounts of SRS-A in unknown samples. The program provided for a correction to adjust for changes in tissue responsiveness. Using this bioassay, we showed that ovalbumin-induced release of SRS-A from sensitized guinea-pig lung was parallel to the release of histamine measured fluorometrically. Ethanol inhibited release of these mediators of anaphylaxis in a similar fashion. Conversely, isoproterenol reduced ovalbumin-induced release of SRS-A to a greater extent than the release of histamine. The versatility of this technique should enable other bioassays to be improved in addition to greatly facilitating the determination of various pharmacologic analyses.
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods; D003201:Computers; D000431:Ethanol / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D006636:Histamine Release / Q000187:drug effects; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008168:Lung / Q000187:drug effects / Q000276:immunology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D013189:SRS-A / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology
chemical_list: D013189:SRS-A; D000431:Ethanol; D007545:Isoproterenol