Effects of glomerular filtration dynamics on the glomerular permeability coefficient

BJ Tucker, RC Blantz - American Journal of Physiology …, 1981 - journals.physiology.org
BJ Tucker, RC Blantz
American Journal of Physiology-Renal Physiology, 1981journals.physiology.org
Studies were performed in Munich-Wistar rats (n= 24) to determine if the glomerular
permeability coefficient (LpA) is affected by changes in the systemic oncotic pressure (pi A)
as well as other determinants of glomerular filtration [nephron plasma flow (RPF) and
glomerular hydrostatic pressure gradient (delta P)] and systemic hematocrit (Hct). Multiple
regression analysis was used to separate the respective relationships of pi A, delta P, RPF,
and Hct to LpA to ascertain whether the correlation of LpA to these variables was direct or …
Studies were performed in Munich-Wistar rats (n = 24) to determine if the glomerular permeability coefficient (LpA) is affected by changes in the systemic oncotic pressure (pi A) as well as other determinants of glomerular filtration [nephron plasma flow (RPF) and glomerular hydrostatic pressure gradient (delta P)] and systemic hematocrit (Hct). Multiple regression analysis was used to separate the respective relationships of pi A, delta P, RPF, and Hct to LpA to ascertain whether the correlation of LpA to these variables was direct or mediated by some concurrently changing factor. Three two-period protocols were used to examine the changes of these determinants of filtration: 1) hydropenia to 10% body wt saline expansion (SE), 2) SE to 1% body wt of concentrated rat plasma protein (25 g/100 ml) solution (HP) with removal of 1.5% body wt whole blood, and 3) SE to 1% body wt HP with 2.5% body wt whole blood removed with reinfusion of the removed erythrocytes. Changes in LpA correlated directly with changes in pi A (P less than 0.01) and inversely with delta P (P less than 0.01). There was no direct correlation of LpA to RPF or consistent correlation of LpA to Hct.
American Physiological Society