366
FINDLAY 2. RUSSELL.
These workers found the venom to be a clear, colorless fluid with a pH
of 6.8, and having a nitrogen content of 2% and a protein content
(biuret) of approximately 13%. The intravenous LD,, in mice was
approximately 200 pg of proteinlkg body weight. On the basis of this
determination they suggested that extracts of the spines from one
fish would contain 10,000 to 25,000 LD50 for mice. The lethal fraction
was non-dialyzable. Lyophilized or glycerol-treated extracts were
found to have retained 50 to 100% of their original lethal activity
following storage for 1 year at -20°C. Intravenous injection of small
amounts of the venom into rabbits produced a slight fall in arterial
blood pressure accompanied by an increase in respiratory rate, with no
electrocardiographic changes. These effects were transient. Larger
doses caused more marked changes in arterial pressure and respiratory
rate, and alterations in the electrocardiogram. With lethal doses
(10 pg protein/kg body weight), these changes were markedly accentuated ; first degree atrioventricular block and ventricular fibrillation
were sometimes seen. In a typical experiment the rabbit died in 90 sec.
I n subsequent experiments, Saunders and his colleagues suggested
that extracts prepared from the dorsal spines of a single fish contained
approximately 3000 LD,, for mice. I n rabbits, the mean intravenous
lethal dose/kg was approximately one-tenth the LD,, for mice. This
amount produced ataxia, paralysis of the limbs and neck, convulsions,
respiratory arrest and death. While respiratory arrest was a terminal
event, artificial respiration was ineffective in prolonging the life of the
animal. On starch gel electrophoresis these investigators found that
the venom contained 7 to 10 bands. Material lethal to mice could be
recovered from only one of these bands. This fraction had an approximate LD,,, in mice, of 15 pg of nitrogen/kg body weight. Re-electrophoresis of this lethal fraction gave a single band.
Wiener (1959a) found that the average yield of venom from a
functional dorsal spine of 8. trachynis was 0.03 ml, or 5.1 to 9.8 mg of
the dried venom. When the toxin was injected intravenously into mice
the LD,, was found to be 0.005 to 0.01 mg/15 g mouse; the subcutaneous LD,, was 0.04 to 0.06 mg, and the intraperitoneal LD,, was
0.02 to 0.03 mg. Lethal amounts of the venom caused muscular
incoordination, paralysis of the hind limbs, irregular respirations, coma
and convulsions. These signs were followed by prostration, cessation
of respiratory movements and cardiac arrest. On opening the thorax,
Wiener found the lungs to be hemorrhagic, “ gelatinous in consistency
and filled with frothy fluid.’’ I n guinea pigs the venom caused necrosis
at the site of injection, muscular weakness, respiratory depression,
coma and death. Examination of the thorax revealed that the lungs
FINDLAY 2. RUSSELL.
These workers found the venom to be a clear, colorless fluid with a pH
of 6.8, and having a nitrogen content of 2% and a protein content
(biuret) of approximately 13%. The intravenous LD,, in mice was
approximately 200 pg of proteinlkg body weight. On the basis of this
determination they suggested that extracts of the spines from one
fish would contain 10,000 to 25,000 LD50 for mice. The lethal fraction
was non-dialyzable. Lyophilized or glycerol-treated extracts were
found to have retained 50 to 100% of their original lethal activity
following storage for 1 year at -20°C. Intravenous injection of small
amounts of the venom into rabbits produced a slight fall in arterial
blood pressure accompanied by an increase in respiratory rate, with no
electrocardiographic changes. These effects were transient. Larger
doses caused more marked changes in arterial pressure and respiratory
rate, and alterations in the electrocardiogram. With lethal doses
(10 pg protein/kg body weight), these changes were markedly accentuated ; first degree atrioventricular block and ventricular fibrillation
were sometimes seen. In a typical experiment the rabbit died in 90 sec.
I n subsequent experiments, Saunders and his colleagues suggested
that extracts prepared from the dorsal spines of a single fish contained
approximately 3000 LD,, for mice. I n rabbits, the mean intravenous
lethal dose/kg was approximately one-tenth the LD,, for mice. This
amount produced ataxia, paralysis of the limbs and neck, convulsions,
respiratory arrest and death. While respiratory arrest was a terminal
event, artificial respiration was ineffective in prolonging the life of the
animal. On starch gel electrophoresis these investigators found that
the venom contained 7 to 10 bands. Material lethal to mice could be
recovered from only one of these bands. This fraction had an approximate LD,,, in mice, of 15 pg of nitrogen/kg body weight. Re-electrophoresis of this lethal fraction gave a single band.
Wiener (1959a) found that the average yield of venom from a
functional dorsal spine of 8. trachynis was 0.03 ml, or 5.1 to 9.8 mg of
the dried venom. When the toxin was injected intravenously into mice
the LD,, was found to be 0.005 to 0.01 mg/15 g mouse; the subcutaneous LD,, was 0.04 to 0.06 mg, and the intraperitoneal LD,, was
0.02 to 0.03 mg. Lethal amounts of the venom caused muscular
incoordination, paralysis of the hind limbs, irregular respirations, coma
and convulsions. These signs were followed by prostration, cessation
of respiratory movements and cardiac arrest. On opening the thorax,
Wiener found the lungs to be hemorrhagic, “ gelatinous in consistency
and filled with frothy fluid.’’ I n guinea pigs the venom caused necrosis
at the site of injection, muscular weakness, respiratory depression,
coma and death. Examination of the thorax revealed that the lungs