232
Reviews
tetrodotoxin structure. The esters were much less toxic than tetrodotoxin following i.p . injection in mice, with lethal doses ranging from 100 to 350 mg per kg . Systolic and diastolic blood pressures were reduced by about 50 per cent in doses of 8 to over 50 mg per kg . The compounds blocked contraction of skeletal muscle in rabbits and cats to indirect stimulation, but only at doses about 10,000 times greater than effective doses of tetrodotoxin, and there is evidence that the action is on neuromuscular transmission, while tetrodotoxin acts principally on nerve axons. The esters had little effect on axonal conduction in desheathed frog nerves, in contrast to tetrodotoxin . The authors consider it unlikely that any single structural group of tetrodotoxin is responsible for its specific action . Possible effects of the guanidine esters on sodium conductance would have to be examined by voltage lamp techniques, but the work reported in this paper suggests that their activity is not closely related to that of tetrodotoxin . P.R .S .
Kos~tct, T. L, SYEPHENS, B. J. and ANDERSON, H. H. (Hawaii Institute of Marine Biology, University of Hawaii, Honolulu, Hawaii), Marine toxins from the Pacific-llI. Comparative bio-assay of ciguatoxin(s) in the mouse and chicken, Proc . west . Pharnr. Soc. 11, 126, 1968 . A sruDY was made of the comparative toxicity in mice and chickens of ciguatoxins prepared from several species of fish . The ciguatoxins tested had been shown to be toxic in the mongoose. The toxin was tested by i.v. and i.p . administration in albino mice (10-20 g) and white legthorn chickens (20-40 g) . The LD yp values obtained following i.v . injection were of the same order of magnitude in mice and chickens . The authors conclude that chickens are sensitive test animals for ciguatoxins and may be used as well as mice for bioassay purposes . P.R .S .
CO1~N, P., DewsoN, J. H. and SEUCMaNN, E. B. (National Institutes of Health, Bethesda, Md .) . Cross-neutralization of Micrurus juh~ires jrrlvius (coral snake) venom by anti-Micrurus carinicauda dumerilii serum. Am . J. trop . Med. Iiyg. 17, 308, 1968 .
ANiTSERUM produced against venom of theColumbian coral snake, Micrurus carinicauda dumerilii neutralized 0'53 mg or about 42 mouse lethal doses of homologous venom per ml and neutralized 021 mg or about 18 mouse lethal doses of North American coral snake (Micrrrrrrs julvius) venom. M. fulvius antiserum neutralized 026 mg or about 23 mouse lethal doses of homologous venom and 024 mg or about 20 mouse lethal doses of M. f. dumertlü venom. Ouchterlony tests show that M. f. dumerilii antiserum contains more precipitating antibody. Availability of venom has been a critical problem in production of adequate supplies of coral snake antivenin. SinceMicrurus c, dwnerllü are more readily wllected in numbers than are M. fulvirrs, it is suggested that this species may be preferable to frt[vius as a source of venom. It is believed that 15 ml of M. c. dumerilii antivenin would neutralize the amount of venom ordinarily injected by an adultNorth American coral snake. S.A .M .
DmLntrrrr, M., BESSLER, H., SANDRANK, U. and DE VRIE4, A. (Beilinson Hospital, Petah Tikva, Israel). Flourescein staining of human lymphocytes induced by Echis colarata venom. Experentta 24,295,1968 .
HUMAN lymphocytes suspended in whole serum or defibrinated plasma stain with fluorescein after incubation with saw-scaled viper (Echis colorata) venom. Venom alone or combined with papain or trypsin does not cause fluorescein uptake. Thrombin is presumed essential for the reaction. Both the procoagulant and protease fractions of the venom are required to produce the effect . It is evidently not due to venom phospholipase A. S .A,M .