Blood pressure and indices of glomerular filtration area in hypertensive and normotensive Prague rats

The involvement of the kidney in the pathogenesis of hypertension has long been recognised, although the specific renal mechanisms underlying this phe nomenon are still unknown. A current hypothesis attributes hyper tension to a reduction in glomerular filtration area by glomerular loss, The present study analyses the relationship between glomerular number and volume and co nscious systolic blood pressure (SBP) in 4- to 53-week-old hypertensive (PH R) and normotensive (PNR) rats of the Prague strain. Adult PHRs had higher SEP, were larger and had larger kidneys than PNRs, but 20% fewer glomeruli, A significant negative correlation between SEP and glomerular number was f ound in PHR males, but not in PHR females or PNRs. There was no correlation at all between glomerular volume and SEP and, in young animals, both SEP a nd glomerular number were higher in PHRs than in PNRs. In addition, in adul t PHRs, glomerular volume and SEP were higher in males than in females. In summary, a generally valid, causal relation-ship linking raised blood press ure to decreased glomerular number or volume could not be demonstrated in t he Prague rat model of genetically determined hypertension. The nature of t he renal mechanism(s) determining the hypertension in this model remains un known. Copyright (C) 2000 S. Karger AG, Basel.