title: Alterations in Ca2+-ATPase activity and calcium-binding protein regucalcin mRNA expression in the kidney cortex of rats with saline ingestion.
abstract: The alteration in calcium metabolism in rats ingested with saline was investigated. Rats were freely given saline as drinking water for 2 and 7 days. Calcium concentration in the serum was significantly elevated by saline ingestion for 2 and 7 days, while serum inorganic phosphorus concentration was not altered. Serum urea nitrogen concentration was significantly increased by saline ingestion for 7 days. Calcium content in the femoral-diaphyseal and metaphyseal tissues was not altered by saline ingestion for 7 days. Calcium content in the kidney cortex was significantly elevated by saline ingestion for 7 days. Ca2+-ATPase activity in the basolsateral membranes of kidney cortex was clearly increased by saline ingestion for 2 and 7 days. The enzyme activity was not altered by the addition of sodium chloride (10(-3) and 10(-2) M), parathyroid hormone (10(-7) and 10(-6) M), and calcitonin (3 x 10(-8) and 3 x 10(-7) M) in the enzyme reaction mixture. A calcium-binding protein regucalcin mRNA expression in the kidney cortex was markedly suppressed by saline ingestion for 7 days, although such a suppression was not seen for 2 days. These results suggest that saline ingestion causes the disturbance of calcium transport system in the kidney cortex of rats, and that the renal disorder may induce hypercalcemia.
authors.affiliation: Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Shizuoka City, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Shinya
authors.forename: M
authors.initials: M
authors.lastname: Yamaguchi
mesh_terms: D000818:Animals; D001806:Blood Urea Nitrogen; D002116:Calcitonin / Q000494:pharmacology; D002118:Calcium / Q000097:blood / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000096:biosynthesis*; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases; D002462:Cell Membrane / Q000201:enzymology; D047908:Intracellular Signaling Peptides and Proteins; D007672:Kidney Cortex / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010281:Parathyroid Hormone / Q000494:pharmacology; D010710:Phosphates / Q000097:blood; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000494:pharmacology; D012982:Sodium, Dietary / Q000494:pharmacology*; D015238:Sulfotransferases; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D002135:Calcium-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D010281:Parathyroid Hormone; D010710:Phosphates; D012333:RNA, Messenger; D012982:Sodium, Dietary; D012965:Sodium Chloride; D002116:Calcitonin; D015238:Sulfotransferases; C028152:alcohol sulfotransferase; D002265:Carboxylic Ester Hydrolases; C513325:Rgn protein, rat; D000252:Calcium-Transporting ATPases; D002118:Calcium