Transforming growth factor beta 1 in essential hypertension and glomerulonephritis: the effects of inhibition of the renin angiotensin system on its serum level in glomerulonephritis

ABSTRACT

This study was carried out on 12 patients with essential hypertension without micro or macroalbuminuria [group I] and 15 patients with chronic glomerulonephritis with mean 24-hour urinary protein = 4.3 + 3.l g/24 hours, [group II], 7 patients had hypertension [group IIa] and 8 patients had normal blood pressure [group IIb]. Ten healthy subjects were taken as controls. Blood urea, serum creatinine, fasting and 2-hour postprandial plasma glucose, urine analysis, 24-hour urinary protein and serum TGF-beta 1 were measured in diseased groups and controls. TGF-beta 1 was significantly higher in group I with essential hypertension [mean +/- SD 80.4 +/- 18.2 ng/dl] and group II with glomerulonephritis. [387.2 +/- 89.0 ng/dl], compared to control group [36.3 +/- 12.9 ng/dl]. In group II, patients with glomerulonephritis mean serum TGF-beta 1 was significantly higher than group I patients with essential hypertension [p <0.001]. In group II, TGF-beta 1 was not significantly different in hypertensive [group IIa] or normotensive patients [group IIb] [mean serum TGF-beta l = 393.3 +/- 92.0 and 379.0 +/- 84.l ng/dl, respectively]. Patients with glomerulonephritis received the angiotensin converting enzyme inhibitor ACE-I [captopril 25-75 mg/day] for four weeks then blood urea, serum creatinine, 24-hour urinary protein and serum TGF-beta 1 were re-estimated. There was significant reduction in both 24-hour urinary protein and TGF-beta 1 after captopril with no significant changes in urea and creatinine. It might be concluded that serum TGF-beta 1is elevated in patients with essential hypertension and glomerulonephritis. In patients with glomerulonephritis the use of ACE-I may reduce proteinuria and serum TGF-beta 1. Reduction of TGF-beta 1 might be a possible mechanism in the reduction of proteinuria in patients with glomerulonephritis, however, other mechanisms cannot be ruled out