Effect of extracellular fluid volume expansion on maximum glucose reabsorption rate and glomerular tubular balance in single rat nephrons
AUTOR(ES)
Baines, Andrew D.
RESUMO
Extracellular fluid volume expansion with isotonic saline (7.5% of body weight) decreased maximum glucose reabsorption rate by rat kidneys at plasma glucose concentrations greater than 30 mM. Glucose reabsorption rate was 30.2 ±1.6 (SE) μmoles/min·g kidney in nonexpanded rats; it was 18.4 ±1.5 μmoles/min·g in volume-expanded rats. Glucose reabsorption determined by micropuncture was 92% complete at the end of accessible superficial proximal convolutions. Volume expansion resulted in a slight but statistically insignificant reduction of maximal glucose reabsorption rate in superficial nephrons from 786 ±35 μμmoles/min·g kidney in nonexpanded rats to 720 ±30 μμmoles/min·g in volume-expanded rats. Superficial nephron filtration rate was increased by volume expansion from 28.8 ±1.2 nl/min·g to 36.6 ±1.5 nl/min·g kidney. In nonexpanded rats, the ratio of glucose reabsorption to glomerular filtration (tmg/sgfr) was similar in superficial and juxtamedullary nephrons. In volume-expanded rats superficial nephron tmg/sgfr was greater than juxtamedullary nephron tmg/sgfr. Juxtamedullary nephron function was measured by puncturing loops of Henle in the exposed papillae of small rats.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=292184Documentos Relacionados
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