Renal and intestinal calcium-binding proteins in normal and uraemic rats.
The effect of chronic uraemia on the concentrations of the 28 kDa renal and 9 kDa intestinal calcium-binding proteins (calbindin-D28K and calbindin-D9K) was investigated in rats. Calbindin-D9K was measured by a competitive enzyme-linked immunoadsorbent assay and calbindin-D28K by rocket immunoelectrophoresis. Chronic uraemia was induced by 5/6 nephrectomy and the results were compared to sham-operated animals. Rats were fed on a diet containing 0.9% calcium and 1.2% phosphorous. Plasma creatinine and plasma urea were elevated in the nephrectomized rats (p less than 0.001), while plasma-1,25-dihydroxycalciferol vitamin D and fractional calcium absorption were unchanged. Plasma parathyroid hormone was significantly elevated in the uraemic rats. The concentration of calbindin-D28K in renal tissue was increased (p less than 0.001) in rats with chronic uraemia and a direct correlation was found between renal calbindin-D28K and plasma urea (p less than 0.05). Intestinal calbindin-D9K correlated inversely with plasma creatinine (p less than 0.05), but the mean level of calbindin-D9K was unchanged in this model of moderate chronic uraemia. Thus, different regulatory mechanisms control levels of calbindin-D9K and calbindin-D28K.
Staun
M
M
Medical Department P, Rigshospitalet, Copenhagen, Denmark.
Egfjord
M
M
Daugaard
H
H
Olgaard
K
K
D000818:Animals; D064092:Calbindin 1; D064026:Calbindins; D002117:Calcitriol / Q000097:blood; D003404:Creatinine / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D007122:Immunoelectrophoresis; D007413:Intestinal Mucosa / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D009392:Nephrectomy; D010281:Parathyroid Hormone / Q000097:blood; D051381:Rats; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D014508:Urea / Q000097:blood; D014511:Uremia / Q000209:etiology / Q000378:metabolism*
C576500:Calb1 protein, rat; D064092:Calbindin 1; D064026:Calbindins; D010281:Parathyroid Hormone; D064030:S100 Calcium Binding Protein G; C576508:S100g protein, rat; D014508:Urea; D003404:Creatinine; D002117:Calcitriol