Tubulo-glomerular feedback activation in humans before and after nephrectomy.

Background/aims: Tubulo-glomerular feedback (TGF) is a key mechanism for controlling glomerular filtration. Nephrectomy for kidney donation provides a good opportunity for studying TGF status before and after a defined loss of renal function.

Methods: A total of 22 kidney donors were studied before and one year after nephrectomy.

Nephrectomy modifies renal angiotensin II effects in kidney donors.

Background: Age, gender, menopausal status, a family history of hypertension, and renal vascular response to angiotensin II are involved in the progression of renal failure from its very beginning.

Methods: In order to investigate their importance on this progression, we measured effective renal plasma flow (ERPF) and glomerular filtration rate (GFR), and calculated glomerular pressure (Pglo) and afferent and efferent arteriole resistances (by means of Gomez formulae) in 26 normotensive kidney donors before and after nephrectomy.

Results: Renal reactivity to angiotensin was the only variable that affected changes in renal and glomerular hemodynamics after the loss of renal tissue: in subjects with greater angiotensin reactivity, higher afferent resistances (Ra) and lower glomerular filtration and pressure before nephrectomy change to higher efferent resistances (Re) and higher Pglo and filtration after nephrectomy.

Acute and long-term effects of ACE inhibition on renal haemodynamics in glomerular and interstitial nephropathies.

Background: Angiotensin-converting enzyme (ACE) inhibitors are the drugs of choice for the treatment of hypertension in patients with non-diabetic nephropathies. However, not every trial has reported better results with ACE inhibitors (ACE-I) than with other drugs. This study investigates whether the acute and chronic effects of ACE inhibition on renal and glomerular haemodynamics are similar in glomerular and interstitial nephropathies.