Document Detail

Unexpected sudden deaths of F344 rats in long-term toxicity studies: relationship between sudden deaths and stomach tube material or feed type.
MedLine Citation:
PMID:  18827452     Owner:  NLM     Status:  MEDLINE    
Sudden deaths of F344 rats (F344/Du Crj (Fischer)) have occurred frequently in the late stage of carcinogenicity studies using stomach tubes. To reduce the sudden deaths, the incidence of sudden deaths was compared in the control groups from 104-week carcinogenicity studies using two different stomach tubes (metal and Teflon) and feeds (pellet and powder). The results indicate that replacing metal tubes with Teflon tubes from the first administration or after week 41 of administration was not effective in reducing the sudden deaths. On the other hand, sudden deaths did not occur at all after changing the feed from pellets to powder after week 44 or 79 of administration. In addition, although decreased body weight and retention of feed in the oral, pharyngeal and laryngeal cavities were observed in the animals that died suddenly, there were no abnormalities in histopathological examination. Therefore, it is suggested that changing the feed from pellets to powder should be effective in reducing the sudden deaths of F344 rats in long-term oral gavage studies or carcinogenicity studies.
Takumi Ohishi; Masahiro Mochizuki; Tomonori Enami; Kazushi Okazaki; Shuzo Okazaki
Publication Detail:
Type:  Comparative Study; Letter    
Journal Detail:
Title:  The Journal of toxicological sciences     Volume:  33     ISSN:  1880-3989     ISO Abbreviation:  J Toxicol Sci     Publication Date:  2008 Oct 
Date Detail:
Created Date:  2008-10-01     Completed Date:  2009-01-16     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7805798     Medline TA:  J Toxicol Sci     Country:  Japan    
Other Details:
Languages:  eng     Pagination:  509-13     Citation Subset:  IM    
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MeSH Terms
Animal Feed
Carcinogenicity Tests / mortality*
Death, Sudden / etiology*
Enteral Nutrition
Rats, Inbred F344
Stainless Steel
Reg. No./Substance:
12597-68-1/Stainless Steel; 9002-84-0/Polytetrafluoroethylene

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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