LETL

Inbr. F20 (1989).

Colour: Black hooded.

Genet. a, h.

Origin: A rat with spontaneous polyurea, polyphagia and polydipsia was found in a colony of outbred Long Evans rats purchased from Charles River in 1982. Selective breeding for diabetes with brother x sister mating was subsequently started at the Tokushima Research Institute, Otsuka Pharmaceutical Co., Japan

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Characteristics

About 30% of rats develop insulin-dependent diabetes mellitus. Onset is abrupt at 8 to 20 weeks, of equal severity in both sexes, and the animals are not obese. Clinical symptoms include hyperglycemia, glycosurea, ketonia, polyurea polydipsia and polyphagia. There is destruction of the pancreatic ß cells and lymphocytic infiltration of the submaxillary and lacrimal glands. There is no significant T lymphopenia, but there is lymphocytic infliltration into the salivary and lacrimal glands. Genetic analysis suggests that the condition involves at least two genes, one of which is linked to RT1^u. A non-diabetic control strain LETO, has been developed from the same base population. The strain has been characterised at 21 marker loci (Kawano et al 1989, Kawano et al, 1991)

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Kawano K., Hirishima T., Mori S., Abe F., Kurosumi M., and Saitoh Y. (1989) A new rat strain with insulin-dependent diabetes mellitus, "LETL". Rat News Lett. 22, 14-15.

Kawano K., Hirashima T., Mori S., Saitoh Y., Kurosumi M., and Natori T. (1991) New inbred strain of Long-Evans Tokushima lean rats with IDDM without lymphopenia. Diabetes 40, 1375-1381.

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INBRED STRAINS OF RATS
Updated 9 Apr. 1998
Michael FW Festing
MRC Toxicology Unit, Hodgkin Building,
University of Leicester, UK