Quantitative Structural Aspects of the Renal Glomeruli of Hypertensive Mice

Abstract

Kidneys of genetically hypertensive and normotensive mice were studied with respect to kidney weight, number and volume of glomeruli, and filtration surface area. The hypertensive animals have a larger kidney weight to body weight ratio and possess fewer glomeruli per kidney. The superficial cortical glomeruli of the hypertensives are slightly smaller in volume than those of the normotensives although the filtration surface area is similar. The juxtamedullary glomeruli of the hypertensives are both smaller in volume and have less filtration surface area. The possible implications of these findings in the development and/or maintenance of hypertension are discussed.

Mechanisms Responsible for Genetic Hypertension in Schlager BPH/2 Mice

“…Hypertensive BPH/2 mice have similar kidney-to-body weight ratio as BPN/3 (Schlager et al, 1979) but have fewer nephrons per kidney (Rosenberg et al, 1982). Morphometric analysis of kidneys from older BPH/2 mice showed none of the characteristic features of renal parenchymal pathology (Rosenberg et al, 1979) indicating that major morphological differences in the kidney are not likely driving the hypertension.…”

“…Morphometric analysis of kidneys from older BPH/2 mice showed none of the characteristic features of renal parenchymal pathology (Rosenberg et al, 1979) indicating that major morphological differences in the kidney are not likely driving the hypertension. However, the available filtration surface area in juxtamedullary glomeruli in BPH/2 mice is less than half that of BPN/3 mice while the superficial cortical glomeruli were comparable between strains (Rosenberg et al, 1982). By contrast, it is the superficial glomeruli in BPH/2 mice that show reduced permeability of the basement membrane compared with BPN/3 mice but not the juxtamedullary glomeruli.…”

“…An important phenotypic difference observed in BPH/2 mice is that their body weight is lower compared with BPN/3 mice (Rosenberg et al, 1982; Buu et al, 1987). However, hypotensive BPL/1 mice also have lower body weight than BPN/3 mice suggesting that this attribute is not likely to be associated with the hypertension (Rosenberg et al, 1979).…”

“…They established an inbred hypertensive strain of mice (BPH/2, Blood Pressure High) that has subsequently been studied in a wide range of investigations. These have described the phenotype, including genetics (Schlager, 1994; Marques et al, 2011a), cardiovascular function (McGuire et al, 2007; Davern et al, 2009), renal function (Rosenberg et al, 1982), behavior (Elias et al, 1975a), as well as involvement of the sympathetic (Davern et al, 2009; Jackson et al, 2013) and central nervous system (Jackson et al, 2014d). Thus, we have reached a point where we know a great deal about the mechanisms involved in producing the higher blood pressure (BP) in this mouse strain.…”