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Experiences with sea snake antivenins and antitoxins
EXPERIENCES WITH SEA SNAKE ANTIVENINS
George V. Marine
Sciences
Division,
Naval
AND ANTITOXINS
Plckwell
Ocean Systems
Center,
San Diego,
California,
USA
Antivenins exhibiting useful titers to sea snake neurotoxins ware obtalned from rabbits within as little as 8 weeks after single lnjectlons of sea snake whole venoms (various species) In Freund’s Complete Adjuvant. Often as llttle as 0.015 mg/kg elicited adequate antibody levels for experimental purposes. Slmllarly, usable titers were obtalned after one or two Injections of purified toxin (erabutoxln a or b) at levels as low as 0.09 mg/kg. Generally, In approprlately responsive animals, a second injection was required to produce identifiable antibody to important secondary venom components such as the presumptive myotoxlc factor. Experiments In maklng usable toxoids from whole venoms by treating with 2 % formaldehyde appeared to destroy all antigenlc sites as Judged by failure to produce preclpltin bands against sea snake antivenln in Ouchterlony dlffuslon. Glutaraldehyde (2 %) conjugated toxolds, however, produced strong single-band reactions in Imnunodlffuslon both with whole venom and purified toxins. This occurred wlth autoconjugates and toxins Jolned to larger molecules such as bovlne serum albumin. Glutaraldehyde toxoids conjugated to hemocyanin when Injected with adJuvant into rabbits failed to elicit slgnlflcantly higher antibody production than raw venom or toxin even when offered In challenge doses 10 times greater. This may have been due to a reduction in antigenlc sites on the toxln molecules arising as a result of the binding to one another and to larger protein molecules. Antlvenins produced from whole venom toxoids Indicated speclflcity only for the maJor neurotoxin component In homologous imnunodlffuslon. This suggests a re duced or negligible production of antibody to the sea snake myotoxic factor. Thus, In clrcumstances where protection agalnst both lethal factors is required, substantially larger quantities of toxoid must be injected, the toxoiding procedure must perhaps be further altered from these generalized methods or a specific antitoxin to the purified myotoxlc factor must be produced and added to the final sea snake antivenin being produced.
140
George V. Marine
Sciences
Division,
Naval
AND ANTITOXINS
Plckwell
Ocean Systems
Center,
San Diego,
California,
USA
Antivenins exhibiting useful titers to sea snake neurotoxins ware obtalned from rabbits within as little as 8 weeks after single lnjectlons of sea snake whole venoms (various species) In Freund’s Complete Adjuvant. Often as llttle as 0.015 mg/kg elicited adequate antibody levels for experimental purposes. Slmllarly, usable titers were obtalned after one or two Injections of purified toxin (erabutoxln a or b) at levels as low as 0.09 mg/kg. Generally, In approprlately responsive animals, a second injection was required to produce identifiable antibody to important secondary venom components such as the presumptive myotoxlc factor. Experiments In maklng usable toxoids from whole venoms by treating with 2 % formaldehyde appeared to destroy all antigenlc sites as Judged by failure to produce preclpltin bands against sea snake antivenln in Ouchterlony dlffuslon. Glutaraldehyde (2 %) conjugated toxolds, however, produced strong single-band reactions in Imnunodlffuslon both with whole venom and purified toxins. This occurred wlth autoconjugates and toxins Jolned to larger molecules such as bovlne serum albumin. Glutaraldehyde toxoids conjugated to hemocyanin when Injected with adJuvant into rabbits failed to elicit slgnlflcantly higher antibody production than raw venom or toxin even when offered In challenge doses 10 times greater. This may have been due to a reduction in antigenlc sites on the toxln molecules arising as a result of the binding to one another and to larger protein molecules. Antlvenins produced from whole venom toxoids Indicated speclflcity only for the maJor neurotoxin component In homologous imnunodlffuslon. This suggests a re duced or negligible production of antibody to the sea snake myotoxic factor. Thus, In clrcumstances where protection agalnst both lethal factors is required, substantially larger quantities of toxoid must be injected, the toxoiding procedure must perhaps be further altered from these generalized methods or a specific antitoxin to the purified myotoxlc factor must be produced and added to the final sea snake antivenin being produced.
140