A study of possible chemical mediators of a hypersensitivity reaction in teleost fishes.

Anderson, Alan Alexander

Abstract

The manifestations of anaphylaxis vary considerably in different species. One common factor appears to be the release of pharmacological mediators, potent biologically-active substances which have a profound effect on vascular and bronchial smooth muscle. A cutaneous anaphylactic reaction in teleost fish has only recently been described and there is little information about the causal mechanisms. As a consequence, this thesis is primarily concerned with the pharmacological mediators of the response and their involvement in the overall reaction mechanism. As a model of cutaneous anaphylaxis, chopped plaice skin was incubated with a fish Ringer saline in the presence of a fungal challenging agent, Epidermophyton floccosum. A mammalian smooth muscle contracting material was found to be released, reaching a maximum after sixty minutes incubation. Initial extraction and purification suggested the presence of a prostaglandin-like substance. Identity was confirmed as prostaglandin E2 by mass spectrometric analysis. In addition, using a continuous perfusion technique in anaesthetized plaice, nanogram quantities of a prostaglandin-like material were recovered in subcutaneous perfusates of skin challenged with E.floccosum. The ability of the skin to synthesize prostaglandin E2 was demonstrated by the incubation of an enzymic preparation from plaice skin with exogenous arachidonic acid. Although indomethacin abolished prostaglandin release from the skin in vitro, it did not inhibit the cutaneous reaction in whole plaice, indicating that other mediators must be involved in addition to prostaglandin. Evidence is presented that histamine, 5-HT and bradykinin are not available in significant quantities in the plaice. Transfer of the skin reaction to flounders was observed after the injection of plaice serum and also of C-reactive protein, a factor purified from plaice serum. The implications with respect to the overall reaction mechanism in plaice are discussed in relation to the phylogenetic development of the animal kingdom.

Citation

ANDERSON, A.A. 1980. A study of possible chemical mediators of a hypersensitivity reaction in teleost fishes. Robert Gordon's Institute of Technology, PhD thesis. Hosted on OpenAIR [online]. Available from: https://doi.org/10.48526/rgu-wt-1993244

• Thesis Type: Thesis
• Deposit Date: Oct 9, 2024
• Publicly Available Date: Oct 9, 2024
• DOI: https://doi.org/10.48526/rgu-wt-1993244
• Public URL: https://rgu-repository.worktribe.com/output/1993244
• Award Date: Feb 29, 1980