T. Noguchi et al., POISONING BY THE RED-ALGA-OGONORI (GRACILARIA-VERRUCOSA) ON THE NOJIMA COAST, YOKOHAMA, KANAGAWA PREFECTURE, JAPAN, Toxicon, 32(12), 1994, pp. 1533-1538
A food poisoning case due to the ingestion of 'ogonori', an edible red
alga, occurred at Yokohama, Kanagawa Prefecture, Japan, in late Octob
er 1993, resulting in two victims, including one death (female). No ca
usative agent present in the ogonori was found from a routine bioassay
for marine toxins. From the production of increased amounts of prosta
glandins (PGs), mainly PGE(2), by the alga on stimulation by cutting o
r soaking in fresh water, and further increase of PGE(2) by addition o
f arachidonic acid, it appeared that an enzyme, probably fatty acid cy
clooxygenase, in the ogonori and the body of the victim, was acting on
the highly unsaturated fatty acids in the oil of the ingested seafood
and in the blood hemorrhaged from the stomach of the victim. This res
ulted in the production of over 30 mg of PGE(2) and small amounts of o
ther PGs in a comparatively short time, With this dosage the victim su
ffered from nausea, vomiting, and hypotension, and died of hypotensive
shock. PGE(2) seems to work more selectively on females. This type of
poisoning is very unusual, and differs from the more familiar forms o
f poisoning occurring after ingestion of marine organisms.