Volume-weighted mean glomerular volume in spontaneously hypertensive rats treated with different doses of spironolactone.

OBJECTIVES Ascertain alterations in volume-weighted glomerular volume in monotherapy of spontaneously hypertensive rats with different doses of spironolactone. MATERIAL AND METHODS We have studied young adult male spontaneously hypertensive rats (SHR) 20 weeks old, divided in 4 groups of 5 animals each: Controls, spironolactone lower dose (5mg/kg/day), spironolactone average dose (10mg/kg/day), and spironolactone higher dose (30mg/kg/day) dissolved in drinking water (for 12 weeks). Serum albumin, blood urea nitrogen (BUN), and creatinine, and the volume-weighted mean glomerular volume (VWGV) were measured. RESULTS Common progress of blood pressure (BP) in young adult SHR was greatly altered by spironolactone treatment, by either attenuation or reversion of BP increasing tendency. Biochemical evaluation of kidney function indicated normal levels for albumin and creatinine, and high levels for BUN in SHR in all groups. Thickened intrarenal arteries and venous stasis were observed in all groups. Treated SHR spironolactone average and higher doses glomeruli presented smaller and more regular profiles; glomerular hypertrophy with glomerular tuft gross disarray in controls and treated SHR spironolactone lower dose was observed. VWGV was significantly greater in control and treated SHR spironolactone lower dose than in treated SHR spironolactone average and higher doses. CONCLUSIONS Monotherapy with spironolactone may affect glomerular size and shape in a dose-dependent way; spironolactone showed a significant effect in preserving VWGV, and may be used associated with other drugs in antihypertensive therapy to prevent secondary effects of hypertension in the kidney.