CONTINUOUS TELEMETRIC BLOOD-PRESSURE MONITORING AND GLOMERULAR INJURYIN THE RAT REMNANT KIDNEY MODEL

The pathogenesis of glomerular injury in the remnant kidney (RK) model remains controversial. Increased glomerular transmission of systemic hypertension has been postulated to be an important pathogenetic mecha nism, but the precise relationship between systemic pressures and glom erular injury has not been defined because of the limitations of the t ail-cuff method. Systolic blood pressure (BP) was continuously recorde d radiotelemetrically at 10-min intervals for 6 wk in rats after appro ximately 5/6 renal ablation (n = 16) or sham ablation (n = 7). Overall mean systolic BP in RK rats was significantly higher than sham (138 /- 3.3 vs. 117 +/- 1.3 mmHg, P < 0.01). Additionally, marked lability of systolic BP was observed in RK rats as compared with sham rats. Glo merular injury was essentially confined to RK rats, but the percentage of injured glomeruli ranged between 1 and 55%. Glomerular injury in i ndividual animals was strongly correlated (r = 0.88) with the mean sys tolic BP during the last approximately 4 wk and with the frequency of systolic BP readings of >140 mmHg. These data strongly suggest that tr ansmission of systemic hypertension to the renal microvasculature play s a predominant role in the pathogenesis of glomerular injury in the R K model and also support the potential usefulness of the radiotelemetr ic technique to investigate hypertensive target organ injury.