Increase in calcium content and Ca(2+)-ATPase activity in the brain of fasted rats: comparison with different ages.
The effect of fasting on calcium content and Ca(2+)-ATPase activity in the brain tissues of 5 weeks and 50 weeks old rats was investigated. Brain calcium content and Ca(2+)-ATPase activity in the microsomal and mitochondrial functions of the brain homogenate from young and elderly rats were significantly increased by overnight-fasting. These increases were appreciably restored by a single oral administration of glucose solution (400 mg/100 g body weight) to fasted rats. In comparison with young and elderly rats, brain calcium content and microsomal Ca(2+)-ATPase activity were significantly elevated by increasing ages. The effect of ageing was not seen in the brain mitochondrial Ca(2+)-ATPase activity. When calcium (50 mg/100 g) was orally administered to young and elderly rats, brain calcium content was significantly elevated. The calcium administration-induced increase in brain calcium content was greater in elderly rats than in young rats. Also, calcium administration caused a significant increase in Ca(2+)-ATPase activity in the microsomal and mitochondrial fractions of brain homogenates from young rats. In aged rats, the microsomal Ca(2+)-ATPase activity was not further enhanced by calcium administration, although the mitochondrial enzyme activity was significantly raised. The present study demonstrates that the fasting-induced increase in brain calcium content is involved in Ca(2+)-ATPase activity raised in the brain microsomes and mitochondria of rats with different ages, supporting a energy-dependent mechanism in brain calcium accumulation.
Hanahisa
Y
Y
Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Japan.
Yamaguchi
M
M
D000367:Age Factors; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000097:blood* / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D005215:Fasting / Q000378:metabolism*; D005260:Female; D051381:Rats; D017208:Rats, Wistar
D000252:Calcium-Transporting ATPases; D002118:Calcium