MARINE TOXINS AND VENOMOUS AND POISONOUS MARINE ANIM~LLS
279
In 1923, Ackermann et al. isolated tetramethyl ammonium hydroxide ( r r tetramine ”) from Actinia equina. Subsequently, he and his
co-workers isolated a number of other quaternary ammonium compounds from cnidarians, many of which have been studied for their
zootoxicological properties. Among the nitrogenous bases so far
studied are N-methylpyridinium hydroxide, homarine, trigonelline,
y-butyrobetaine and zooanemonin. Of this group, tetramine alone is
associated with a curare-like activity, although it does not appear to
have any deleterious effect on certain crustacean nerve-muscle preparations (Cowan and Ing, 1935). Also, the amount present in the animal
hardly seems sufficient to produce the activity with which it has been
implicated. Tetramine is a common constituent of several cnidarian
tissues and has been suggested as a transmitter substance in cnidarian “ nerve activity ”. It is possible that while it may not be the
substance directly responsible for the paralyzing effect of the toxin,
it contributes in a significant way to the development of this activity.
It must be concluded that although tetramine is present in the extracts
from tentacles and other parts its exact role as a toxin in cnidarian
venom has not yet been established.
5-Hydroxytryptamine (5-HT, serotonin) has been identified in a
number of cnidarians (Welsh, 1960), and is a common constituent
of many venoms (Erspamer, 1961). In Cnidaria it is found in the
tentacles, body wall, acontia, and several other parts. There is always
a particularly high concentration in those parts where nematocysts
are concentrated. 5-HT is, of course, a potent pain-producing substance
in man, although the mechanism by which it causes pain is not known.
It may provoke changes in the permeability of sensory nerve endings,
thereby altering the transfer of ions to receptor sites, or it may be
concerned with the transport and distribution of certain ions about
the nerve endings. As a potent vasoconstrictor it may effect circulation
about the sensory nerve endings and thus induce changes leading to the
development of pain. While it no doubt contributes to the painproducing effect of the toxin it is not the only pain producer in the
venom.
Finally, 5-HT may contribute directly to the mechanism through
which certain of the local effects are produced. It may cause changes
resulting in localized edema and itching, as well as the changes responsible for the vascular effects and hemorrhage. On the other hand,
it is a potent histamine releaser and along with histamine and other
histamine releasers (Uvnas, 1960) in the toxin may contribute to the
localized changes. It is absorbed very slowly from the skin and subcutaneous tissues. It is not an important factor in the lethal or para-
279
In 1923, Ackermann et al. isolated tetramethyl ammonium hydroxide ( r r tetramine ”) from Actinia equina. Subsequently, he and his
co-workers isolated a number of other quaternary ammonium compounds from cnidarians, many of which have been studied for their
zootoxicological properties. Among the nitrogenous bases so far
studied are N-methylpyridinium hydroxide, homarine, trigonelline,
y-butyrobetaine and zooanemonin. Of this group, tetramine alone is
associated with a curare-like activity, although it does not appear to
have any deleterious effect on certain crustacean nerve-muscle preparations (Cowan and Ing, 1935). Also, the amount present in the animal
hardly seems sufficient to produce the activity with which it has been
implicated. Tetramine is a common constituent of several cnidarian
tissues and has been suggested as a transmitter substance in cnidarian “ nerve activity ”. It is possible that while it may not be the
substance directly responsible for the paralyzing effect of the toxin,
it contributes in a significant way to the development of this activity.
It must be concluded that although tetramine is present in the extracts
from tentacles and other parts its exact role as a toxin in cnidarian
venom has not yet been established.
5-Hydroxytryptamine (5-HT, serotonin) has been identified in a
number of cnidarians (Welsh, 1960), and is a common constituent
of many venoms (Erspamer, 1961). In Cnidaria it is found in the
tentacles, body wall, acontia, and several other parts. There is always
a particularly high concentration in those parts where nematocysts
are concentrated. 5-HT is, of course, a potent pain-producing substance
in man, although the mechanism by which it causes pain is not known.
It may provoke changes in the permeability of sensory nerve endings,
thereby altering the transfer of ions to receptor sites, or it may be
concerned with the transport and distribution of certain ions about
the nerve endings. As a potent vasoconstrictor it may effect circulation
about the sensory nerve endings and thus induce changes leading to the
development of pain. While it no doubt contributes to the painproducing effect of the toxin it is not the only pain producer in the
venom.
Finally, 5-HT may contribute directly to the mechanism through
which certain of the local effects are produced. It may cause changes
resulting in localized edema and itching, as well as the changes responsible for the vascular effects and hemorrhage. On the other hand,
it is a potent histamine releaser and along with histamine and other
histamine releasers (Uvnas, 1960) in the toxin may contribute to the
localized changes. It is absorbed very slowly from the skin and subcutaneous tissues. It is not an important factor in the lethal or para-