In this study, 10 female SDT rats and 10 female SDT fatty rats (both from Clea Japan, Tokyo, Japan) were used. SDT rat is a spontaneously diabetic strain of the Sprague-Dawley (SD) rats
[42 (link)], and loci for glucose intolerance have been identified [28 (link)]. The SDT fatty rat was established by
inserting the leptin gene into the genome of the SDT rat [29 (link)]. Moreover, age-matched 10 female SD rats (Clea Japan) were also used as control animals.
The experiment was conducted in strict compliance with our own Laboratory Guidelines for Animal Experimentation and was approved by the Institutional Animal Care and Use Committee of Central
Pharmaceutical Research Institute of Japan Tobacco Inc. Rats were housed in a climate-controlled room (temperature 23 ± 3°C, humidity 55 ± 15%, 12 hr/12 hr light-dark cycle). A basal diet
(CRF-1, Oriental Yeast, Tokyo, Japan) and sterilized water were provided ad libitum. Initially, 10 SDT fatty rats were provided, but 4 out of 10 died by 58 weeks of age.
Therefore, the remaining 6 rats were assigned to 4 rats for biochemical parameter measurements and morphological studies, and 2 rats for mRNA analysis. In the previous study using male rats,
morphological changes in the brain were observed at 58 weeks but not at 32 weeks [26 (link)], so the following measurements were performed at 58 weeks of
age.
[42 (link)], and loci for glucose intolerance have been identified [28 (link)]. The SDT fatty rat was established by
inserting the leptin gene into the genome of the SDT rat [29 (link)]. Moreover, age-matched 10 female SD rats (Clea Japan) were also used as control animals.
The experiment was conducted in strict compliance with our own Laboratory Guidelines for Animal Experimentation and was approved by the Institutional Animal Care and Use Committee of Central
Pharmaceutical Research Institute of Japan Tobacco Inc. Rats were housed in a climate-controlled room (temperature 23 ± 3°C, humidity 55 ± 15%, 12 hr/12 hr light-dark cycle). A basal diet
(CRF-1, Oriental Yeast, Tokyo, Japan) and sterilized water were provided ad libitum. Initially, 10 SDT fatty rats were provided, but 4 out of 10 died by 58 weeks of age.
Therefore, the remaining 6 rats were assigned to 4 rats for biochemical parameter measurements and morphological studies, and 2 rats for mRNA analysis. In the previous study using male rats,
morphological changes in the brain were observed at 58 weeks but not at 32 weeks [26 (link)], so the following measurements were performed at 58 weeks of
age.