title: Elevated cytosolic calcium of adipocytes in chronic renal failure.
abstract: Chronic renal failure (CRF) is associated with increased calcium content of, and impaired lipase release from lipid cells. This has been attributed to a rise in the cytosolic calcium ([Ca2+]i) of these cells. However, data on [Ca2+]i of lipid cells in CRF and on the mechanisms responsible for such an abnormality are lacking. To study this issue we examined the [Ca2+]i and ATP content of lipid cells and Vmax of Na(+)-K(+)-ATPase and Ca2+ ATPase of membrane preparation and Na(+)-Ca2+ exchange of membrane vesicles of adipocytes from normal rats, 6 week CRF, CRF normocalcemic parathyroidectomized (CRF-PTX) and CRF, and normal rats treated with verpamil (CRF-V, normal-V). [Ca2+]i in adipocytes of CRF rats was higher (199 +/- 8.5 nM) and ATP lower (2.9 +/- 0.31 nmol/10(6) cells) than in normal (120 +/- 4.3 nM; 5.7 +/- 0.27 nmol/10(6) cells), CRF-PTX (128 +/- 4.7 nM; 5.8 +/- 0.39 nmol/10(6) cells), normal-V (121 +/- 3.2 nM; 5.3 +/- 0.36 nmol/10(6) cells), CRF-V (123 +/- 7.4 nM; 5.5 +/- 0.30 mmol/10(6) cells). Vmax Ca2+ ATPase and the activity of Na(+)-K(+)-ATPase and of Na(+)-Ca2+ exchanger were reduced in CRF rats as compared to the other four groups of rats. The values in normal, CRF-PTX, CRF-V and normal-V rats were not different.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, University of Southern California, School of Medicine, Los Angeles, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Ni
authors.forename: M
authors.initials: M
authors.lastname: Smogorzewski
authors.forename: S G
authors.initials: SG
authors.lastname: Massry
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D017667:Adipocytes / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism*; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000145:classification; D016105:Parathyroidectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000502:physiology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014700:Verapamil / Q000494:pharmacology
chemical_list: D010281:Parathyroid Hormone; D000255:Adenosine Triphosphate; D012964:Sodium; D014700:Verapamil; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium