Effects of methylprednisolone and uremia on renal and intestinal calbindin-D in the rat.
The effects of glucocorticoids on renal and intestinal calcium binding protein (calbindin-D28K and calbindin-D9K) were examined in normal and uremic rats. Chronic uremic rats and normal controls were treated with either methylprednisolone (MP) 1.3 mg/kg/d or isotonic saline given as a continuous intraperitoneal infusion for 1 week before sacrifice. Renal calbindin-D28K was measured by rocket immunoelectrophoresis and intestinal calbindin-D9K was measured by an enzyme-linked immunoadsorbent assay. Methylprednisolone treatment of chronic uremic rats increased plasma phosphate levels (P < 0.05), but plasma calcium and 1,25-dihydroxyvitamin D3 were unchanged in all groups. MP treatment did not affect the renal calbindin-D28K in either normal or uremic rats. In normal rats, MP treatment reduced intestinal calbindin-D9K by 28% when compared to placebo (P < 0.05). In contrast, chronic uremia increased renal calbindin-D28K by 51% and 38% (P < 0.001) in placebo and MP treated uremic rats, respectively, while intestinal calbindin-D9K was unchanged. Thus, MP treatment and chronic uremia induced different changes in renal and intestinal calbindin-D of the rat suggesting that different mechanisms are involved in the regulation of these vitamin D dependent proteins.
Egfjord
M
M
Department of Medicine P, Rigshospitalet, Copenhagen, Denmark.
Staun
M
M
Olgaard
K
K
D000818:Animals; D001806:Blood Urea Nitrogen; D064092:Calbindin 1; D064026:Calbindins; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000097:blood; D003404:Creatinine / Q000097:blood; D005260:Female; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008775:Methylprednisolone / Q000494:pharmacology*; D010710:Phosphates / Q000097:blood; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D014511:Uremia / Q000378:metabolism*
C576500:Calb1 protein, rat; D064092:Calbindin 1; D064026:Calbindins; D010710:Phosphates; D011506:Proteins; D064030:S100 Calcium Binding Protein G; C576508:S100g protein, rat; D003404:Creatinine; D002117:Calcitriol; D002118:Calcium; D008775:Methylprednisolone