الفهرس 
Poisonous fishesOnly 14 pages are availabe for public view
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Abstract
A crude toxic extrsct was prepared frord tlie skin of a Xed sea fish cal led f9-k-D-& bon hisnidusN belonging -4- t o the faxilily li’etraodontidas of the order Pleotogna’chi. The ini;raperitoncal inin.ii;xil 1e.L-h=.li! o s c of the cwde toxic exCract was fouid to be 164.2 mg/lz body weight i n albino r.~tsi,l nd 300 mg/kg body msfghi. i n dogs. This le’chal effect decreased by storing i-his crude extmo-i; i n the dry state while it reimincd unaffe~ted if it was preserved i n ethyl alcohol, 2. Y11a in-trovenous iri jection of this crude toxio extract into intact ai~eesthetised dogs i n a dose of 300 &kg body rne1gh-b resulted i n apasa a f t e r a brief period 02 increased depth and ra-be of respiration. Also %he blood pressure vas markedly znd rapidly lowered towards the zero level. Pinally the aniiucl died within a period cx1 5 minutes. Apnea was found to be the prime cause of fieath, since t*e survival of the ailiiual my be prolonged by a r t i f i c i a l yespiration. 30 The intravenous injection of this cruds tmin into in.bact cxlzyljle was dimii-l.j.shed by 67.4 precentt 4. The depressand; effect of this toxin OIL the qirculatory and respixat oxy sgst ems was not ref lewely gxoduced via the barorscep-bops of vasosensoxy areas or the chemomoepl-ox:. of the caxo-bid and aortic bodies. 5. Perfusioo of the dog’s head showed ”chat this toxin has a direot depressant effect 0x1 the medulla2y respira2; ory nu3 vasoznotor ceiitres ~e~~ltini iap~nega and severe 1iypo%el1sion respi.c%ively. 6. 1i1 spinal dogs, this toxin also produced marked rwid lowering of the blood pressure, This shows thak .khe hypo-i;ensivs ackion of this toxin is in part due to its ef%eots on ceatres o r structures below the medullary cent~es, f o r exarilgle, it rmy be due t o inhibi%ion of spinal vasocons.t;rictor centre; ganglion bloclcing eff ecf or a direot dilating action on the vessel vall, separately or combined. Perf usion of the hind limb ilemons-brated that this %oxin has a direct vasodilator action on bbe vessel wall. 7. Oil the dmemated heart of the heart-lung preparation this toxia ( i n a dose of 300 mg/lOO 1111 blood) produosd a tenporasy depressant effect on. the qocardium. Also it caused significant lowering of the heart rate, minute ~olumcw hile the coronary blood fl ~mwas significantly inoreased* When large doses of the toxin were added to the blood of the heart-lung preparation ventricular f ib~illatiiono cour~ed. 8. In the isolated toad’s gasZ;rocnen*ius-soia-tic preparation, the crude toxin blocked the conduction of impulse in neme f ib-s after 1.86 minutes on the average, when it was put on the sciatic nerve in a dose of 1 r i in one nl Riuge~bss olui-ion.. Al s o tl~ca ddi-tion of this toxin in the sane dose to the gastrocnemius ji~uscle, resulted in rapid dealine in i-ts response to indirect st imula’cioil, urbil ooqlete paralysis issued wi-Lhin 3.5 minutes 013. the average. The addition 09 tubocurarine t o this muscle in a dose of 20 - 200 microgram did not result in recovery fzom this block. Therear-be]: the muscle contra& ed i n response t o di rect ~ti~nulabiooini ly when the ixt-isity of ths induced current was increased and slio~st hat the t oxin zPf cots minly the ije-mc and neuromusoular junction while it has a slight direct depressanC action on the muscle. Also the toxin significai-rtly lowered the oholines’cerase activity of t-ho mus~le by 51 psrcen* on the average. 9. The above findings were d.iacussed,