AJP - Renal Physiology, Vol 245, Issue 4 419-F424, Copyright © 1983 by American Physiological Society
Chloride-depletion alkalosis with a normal extracellular fluid volume
R. G. Luke and J. H. Galla
Current concepts hold that volume expansion is essential to the correction
of chloride-depletion alkalosis (CDA) with chloride repletion in a
permissive role. In this scheme, intranephronal fluid reabsorption would be
redistributed with increased delivery to the distal nephron where the
provided chloride is readily reabsorbed and the limited capacity for
bicarbonate reabsorption would promote bicarbonate excretion and correction
of CDA. In a model of CDA produced by peritoneal dialysis against 0.15 M
NaHCO3, we have shown complete correction of CDA within 24 h without volume
expansion by either oral isotonic sodium or chloride salts with 70 mM
chloride and despite an obligatory bicarbonate load and negative sodium and
potassium balance. During correction of CDA without volume expansion in
rats by intravenous isotonic fluids containing 80 mM chloride, fractional
fluid and chloride reabsorptions in the proximal convoluted tubule and in
the loop segment of superficial nephrons were not different from controls
but chloride reabsorption was enhanced in the collecting duct segment and
probably within the distal convolution. Despite no differences in serial
hematocrits, blood pressure, and measured plasma volume, kidney and nephron
glomerular filtration rate (GFR) were reduced in CDA and returned to normal
upon recovery 24 h later.(ABSTRACT TRUNCATED AT 250 WORDS)
