Kinetics of Glucose Decarboxylation in the Substrate-Limited Isolated Perfused Kidney
Autor: | Julius J. Cohen, Nasr H. Anaizi |
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Rok vydání: | 1991 |
Předmět: |
Radioisotope Dilution Technique
Decarboxylation Sodium Kinetics Renal function chemistry.chemical_element In Vitro Techniques Kidney medicine Animals Carbon Radioisotopes Chromatography Chemistry Albumin General Medicine Metabolism Carbohydrate Rats Perfusion Glucose medicine.anatomical_structure Biochemistry Nephrology Lactates Cardiology and Cardiovascular Medicine |
Zdroj: | Kidney and Blood Pressure Research. 14:81-91 |
ISSN: | 1423-0143 1420-4096 |
DOI: | 10.1159/000173391 |
Popis: | Rat kidneys were perfused with a cell-free perfusate containing substrate-free albumin, different glucose concentrations (0.20–5.0 mmol/l), and uniformly labeled 14C-glucose. The rate of glucose decarboxylation (Qox), as a function of [glucose]p, displayed saturation kinetics [Vmax = 0.35 µmol/(g · min); Km = 0.87mmol/l]; saturation occurred at [glucose]p = 1.0–2.0mmol/l. Although the presence of as low as 0.2mmol/l of glucose significantly increased fractional sodium reabsorption (%TNa), there was no correlation between [glucose]p or Qox and %TNa. However, free water clearance (CH2O or CH2O/GFR) was directly proportional to [glucose]p and independent of Qox. We conclude that (1) in the absence of other substrates, renal glucose Qox saturates at hypoglycemic levels of glucose and (2) glucose plays an important role in the generation of solute-free water, a role that is unrelated to glucose Qox. |
Databáze: | OpenAIRE |
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