title: Maturation-associated changes in toxicity of the pufferfish Takifugu poecilonotus.
abstract: From October 2006 to December 2007, wild specimens of the pufferfish Takifugu poecilonotus (93 females, 45 males) were collected from the Ariake Sea. Tissue toxicity was examined by mouse bioassay, and tetrodotoxin (TTX) content in the blood plasma by enzyme-linked immunosorbent assay. The relationship between toxicity and maturation was investigated based on changes in the gonadosomatic index: December-March in females and November-March in males, the 'maturation period'; April, 'just after spawning'; and the other months, the 'ordinary period'. Toxicity of both sexes was high throughout the year, but sharply declined in April. In all tissues examined (skin, liver, and ovary) other than testis, toxicity exceeded 1000 MU/g or 10,000 MU/individual in many individuals. Seasonal profiles of tissue toxicity differed markedly between sexes. In females, liver toxicity was high during the ordinary period, and ovary toxicity was high during the maturation period. In males, little maturation-associated change in the toxin distribution was observed. Plasma TTX levels were similar between the sexes (1.59-15.1 MU/ml), and fluctuated largely throughout the year without corresponding changes in tissue toxicity. The percentage of TTX binding to high molecular-weight substances in the plasma varied in association with maturation; the binding ratio fluctuated at relatively low levels during the ordinary period, and stabilized at a high level during the maturation period.
authors.affiliation: Graduate School of Science and Technology, Nagasaki University, Nagasaki 852-8521, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Ikeda
authors.forename: Yu
authors.initials: Y
authors.lastname: Emoto
authors.forename: Ryuhei
authors.initials: R
authors.lastname: Tatsuno
authors.forename: Jun Jie
authors.initials: JJ
authors.lastname: Wang
authors.forename: Laymithuna
authors.initials: L
authors.lastname: Ngy
authors.forename: Shigeto
authors.initials: S
authors.lastname: Taniyama
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Takatani
authors.forename: Osamu
authors.initials: O
authors.lastname: Arakawa
mesh_terms: D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006128:Growth / Q000187:drug effects; D008099:Liver / Q000254:growth & development / Q000378:metabolism; D008297:Male; D008387:Marine Toxins / Q000096:biosynthesis / Q000633:toxicity*; D051379:Mice; D010053:Ovary / Q000254:growth & development / Q000502:physiology; D010949:Plasma / Q000737:chemistry; D012621:Seasons; D012727:Sex Characteristics; D012867:Skin / Q000254:growth & development / Q000378:metabolism; D013737:Testis / Q000254:growth & development / Q000502:physiology; D023721:Tetraodontiformes / Q000254:growth & development* / Q000378:metabolism*; D013779:Tetrodotoxin / Q000096:biosynthesis / Q000097:blood
chemical_list: D008387:Marine Toxins; D013779:Tetrodotoxin