PMID- 9458005
OWN - NLM
STAT- MEDLINE
DCOM- 19980217
LR  - 20190819
IS  - 0300-483X (Print)
IS  - 0300-483X (Linking)
VI  - 124
IP  - 2
DP  - 1997 Dec 26
TI  - Toxaphene congeners differ from toxaphene mixtures in their dysmorphogenic 
      effects on cultured rat embryos.
PG  - 153-62
AB  - The presence of persistent organic pollutants, including the pesticide toxaphene 
      has been reported even in remote regions such as the Arctic and is becoming a 
      health concern. The technical mixture of toxaphene contains over 800 different 
      congeners. The numbers of prevalent congeners, however, decrease along the food 
      chain. About 20 major congeners are found in fish, eight in marine mammals and 
      only two major ones in human, 
      2-exo,3-endo,5-exo,6-endo,8,8,10,10-octachlorobornane (T2) and 
      2-exo,3-endo,5-exo,6-endo,8,8,9,10,10-nonachlorobornane (T12). Embryotoxicity of 
      these individual congeners is not known, as previous studies focused on the 
      toxaphene technical mixture. We studied the relative dysmorphogenic activity of 
      toxaphene technical mixture and individual congeners (T2 and T12) using rat 
      embryo culture. Explanted embryos (0-2 somites) were treated for 48 h with 
      concentrations of 0 (DMSO 0.01%), 100, 1000 and 5000 ng/ml of either (a) 
      toxaphene technical mixture; (b) T2; (c) T12; or (d) a 50:50 mixture of T2 and 
      T12. The treatment period corresponds to gestational days (GD) 10-12, a period 
      within the critical time of morphogenesis and organogenesis. Both the technical 
      mixture and the two individual congeners had a significant adverse effects on the 
      total morphological score, somite number, head and crown rump length and the 
      central nervous system scores of embryos. All treatments caused a high incidence 
      of central nervous system defects. The T2 and T12 congeners differed in their 
      spectrum of abnormalities as exposure to T2 caused limb and flexion defects which 
      were not observed with the T12 congener. Differences were also observed in the 
      type of toxicity and the target sites between the technical mixture and the 
      congeners. T2 showed a more potent adverse effect on the morphological score as 
      compared to the technical mixture. Both T2 and T12 were less inhibitory on growth 
      than the technical mixture as indicated by crown-rump length but they showed a 
      stronger inhibitory effect on otic system development. The mixture of T2 + T12 
      showed a synergistic effect on decreasing crown-rump and head length. Conversely, 
      the combination of T2 and T12 inhibited the strong adverse effect of the 
      individual congeners on otic development. The results suggest environmentally 
      predominant toxaphene congeners can have organ specific embryotoxic effects not 
      predicted by the toxaphene technical mixture.
FAU - Calciu, C
AU  - Calciu C
AD  - School of Dietetics and Human Nutrition, Macdonald Campus of McGill University, 
      Ste-Anne-de-Bellevue, Quebec, Canada.
FAU - Chan, H M
AU  - Chan HM
FAU - Kubow, S
AU  - Kubow S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Ireland
TA  - Toxicology
JT  - Toxicology
JID - 0361055
RN  - 0 (Carcinogens)
RN  - 0 (Insecticides)
RN  - 8001-35-2 (Toxaphene)
SB  - IM
MH  - Animals
MH  - Carcinogens/administration & dosage/metabolism/*toxicity
MH  - Chi-Square Distribution
MH  - Embryo, Mammalian/anatomy & histology/*drug effects/metabolism
MH  - Embryonic Structures/drug effects
MH  - Female
MH  - Insecticides/administration & dosage/metabolism/*toxicity
MH  - Morphogenesis/*drug effects
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Toxaphene/administration & dosage/metabolism/*toxicity
EDAT- 1998/02/11 00:00
MHDA- 1998/02/11 00:01
CRDT- 1998/02/11 00:00
PHST- 1998/02/11 00:00 [pubmed]
PHST- 1998/02/11 00:01 [medline]
PHST- 1998/02/11 00:00 [entrez]
AID - S0300-483X(97)00145-5 [pii]
AID - 10.1016/s0300-483x(97)00145-5 [doi]
PST - ppublish
SO  - Toxicology. 1997 Dec 26;124(2):153-62. doi: 10.1016/s0300-483x(97)00145-5.