MARINE TOXINS AND VENOMOUS AND POISONOUS MARINE ANIMALS
353
produces a slight increase in rate. With slightly larger doses there may
be either an increase or decrease in rate, and with lethal doses there is
usually a decrease in rate leading to complete cessation of respirations.
It is always difficult to interpret such respiratory changes in the
presence of profound alterations in the parameters of the cardiovascular system. It would not be feasible in this review to discuss the
possible relationships between the changes in the two systems. We
have attempted to do this in our several publications. Here, it is sufficient to observe that the present evidence indicates that a part of the
respiratory crisis can be attributed to the changes in the cardiovascular
system. It should be noted that neither continuous artificial respiration
or direct stimulation of the diaphragm significantly alters the cardiovascular crisis, nor do these measures save the life of the animal (Russell
and Emery, 1960).
Carlisle (1962) found that the dialyzable fraction of the venom
produced the stabbing pain characteristic of the whole venom, when he
injected it into himself. The non-dialyzable fraction failed to provoke
the pain but did produce a rise in pulse rate and some respiratory
distress. He concluded that the systemic effects of the toxin were due
to the non-dialyzable fraction, while the pain was a consequence of
some constituent of the dialyzable part of the venom. He also discovered that the dialyzable fraction contained a large amount of
5-hydroxytryptamine, and that it was associated with a substance of
low molecular weight which acted as a histamine releaser. The nondialyzable fraction contained a neutral amino polysaccharide lacking
in sulfur, and two separate albumins. Carlisle suggested that these
three substances may not exist separately, but may “ represent a
complex muco-substance of combined polysaccharide-protein nature.”
Skeie has recently published several papers on the weeverfishes
and their venoms. Although he describes all other studies as “ rather
haphazard ” ( 1962a) and criticizes certain investigations and methods,
as well as the compendium of knowledge, his own studies generally
confirm the findings of previous investigations. He describes (1962b)
a technique for extracting the venom from opercular spines. The
method is similar to that which has been employed for extracting
venom from certain other fishes and should be of particular value
where large numbers of weevers me available. As Skeie notes, even
with this method “ a rather large amount of solid sediment consisting
of cell remnants and a few unavoidable scales ” are obtained. Using
this technique he extracted the toxin from 600 weevers into 60 ml of
solution. He found the DML,,, (LD,,,) in two mice to be 0.0004 ml.
On the basis of this formula he calculated that each weever contained
A. 1. n.-S
T
353
produces a slight increase in rate. With slightly larger doses there may
be either an increase or decrease in rate, and with lethal doses there is
usually a decrease in rate leading to complete cessation of respirations.
It is always difficult to interpret such respiratory changes in the
presence of profound alterations in the parameters of the cardiovascular system. It would not be feasible in this review to discuss the
possible relationships between the changes in the two systems. We
have attempted to do this in our several publications. Here, it is sufficient to observe that the present evidence indicates that a part of the
respiratory crisis can be attributed to the changes in the cardiovascular
system. It should be noted that neither continuous artificial respiration
or direct stimulation of the diaphragm significantly alters the cardiovascular crisis, nor do these measures save the life of the animal (Russell
and Emery, 1960).
Carlisle (1962) found that the dialyzable fraction of the venom
produced the stabbing pain characteristic of the whole venom, when he
injected it into himself. The non-dialyzable fraction failed to provoke
the pain but did produce a rise in pulse rate and some respiratory
distress. He concluded that the systemic effects of the toxin were due
to the non-dialyzable fraction, while the pain was a consequence of
some constituent of the dialyzable part of the venom. He also discovered that the dialyzable fraction contained a large amount of
5-hydroxytryptamine, and that it was associated with a substance of
low molecular weight which acted as a histamine releaser. The nondialyzable fraction contained a neutral amino polysaccharide lacking
in sulfur, and two separate albumins. Carlisle suggested that these
three substances may not exist separately, but may “ represent a
complex muco-substance of combined polysaccharide-protein nature.”
Skeie has recently published several papers on the weeverfishes
and their venoms. Although he describes all other studies as “ rather
haphazard ” ( 1962a) and criticizes certain investigations and methods,
as well as the compendium of knowledge, his own studies generally
confirm the findings of previous investigations. He describes (1962b)
a technique for extracting the venom from opercular spines. The
method is similar to that which has been employed for extracting
venom from certain other fishes and should be of particular value
where large numbers of weevers me available. As Skeie notes, even
with this method “ a rather large amount of solid sediment consisting
of cell remnants and a few unavoidable scales ” are obtained. Using
this technique he extracted the toxin from 600 weevers into 60 ml of
solution. He found the DML,,, (LD,,,) in two mice to be 0.0004 ml.
On the basis of this formula he calculated that each weever contained
A. 1. n.-S
T