The Munich Wistar Frömter rat: proteinuria and blood pressure in correlation to the number of superficial glomeruli.
Rats with a high number of superficial nephrons (MWF/Ztm) also show an elevated urinary protein excretion and a high systolic blood pressure. To investigate a possible correlation between the number of superficial glomeruli and these physiological changes, MWF/Ztm rats were crossed and backcrossed to Wistar cryptorchic (WC/Ztm) animals with no superficial nephrons in order to produce genotypes with differing numbers of superficial glomeruli. In the parental strains, the F1 hybrids and the 8 possible backcrosses, the number of superficial glomeruli, the distance of the 10 most superficial glomeruli to the renal surface, and the diameter of Bowman's capsules were determined by morphometric analysis. The excretion of total protein, in detail low molecular weight proteins, albumin, and high molecular weight proteins were measured quantitatively in 5 males of each genotype. Systolic blood pressure was determined by a tail-cuff method in conscious rats. Means of each variate of the 12 available genotypes were linearly correlated and demonstrate a close correlation between the amount of superficial nephrons and the observed physiological changes, i.e. the more superficial the glomeruli the higher the urinary protein excretion, especially albumin, and the higher the systolic blood pressure.
Hackbarth
H
H
Institut für Versuchstierkunde, Medizinische Hochschule Hannover, BRD.
Gwinner
W
W
Alt
J M
JM
Hagemann
I
I
Thiemann
A
A
Finke
B
B
D000419:Albuminuria / Q000209:etiology; D000818:Animals; D001794:Blood Pressure; D003433:Crosses, Genetic; D005838:Genotype; D007678:Kidney Glomerulus / Q000502:physiology*; D008297:Male; D011507:Proteinuria / Q000209:etiology*; D051381:Rats; D011919:Rats, Inbred Strains