L-arginine-induced vasodilation of the renal vasculature is preserved in uremic type 1 diabetic patients after kidney and pancreas but not after kidney-alone transplantation.
OBJECTIVE
In uremic type 1 diabetic patients, kidney and pancreas transplantation (KP) and kidney-alone transplantation (KD) provide full restoration of normal renal function; however, only KP, i.e., curing diabetes, is expected to prevent endothelial damages. Our aim was to study L-arginine-induced vasodilation of the renal vasculature in uremic type 1 diabetic patients after KP or KD using magnetic resonance (MR).


METHODS
MR quantitative flow measurements were performed in 15 KP patients (mean age 39.0 +/- 1.7 years, 10 men and 5 women), in 11 KD patients (mean age 47.3 +/- 1.9 years, 7 men and 4 women), and in 8 nondiabetic kidney transplant patients (mean age 44.0 +/- 4.8 years, 7 men and 1 woman), who were used as control subjects, to measure renal blood flow and velocity and renal vascular resistance before and immediately after infusion of L-arginine.


RESULTS
Renal blood flow and velocity were not different at baseline in KP, KD, and control subjects. In contrast, during L-arginine administration renal blood flow increased significantly in KP subjects (basal 8.4 +/- 0.6 vs. post 9.6 +/- 0.8 ml/s, Delta 14.3 +/- 4.4%, P < 0.05) and in control subjects (basal 9.3 +/- 0.8 vs. post 9.1 +/- 0.8 ml/s, Delta 17.3 +/- 6.2%, P < 0.01), while it remained unchanged in KD subjects (basal 10.0 +/- 0.8 vs. post 11.6 +/- 0.9 ml/s, Delta -1.36 +/- 6.9%, NS). Parallel results have been achieved for renal blood velocity (KP subjects: 20.1 +/- 4.9%, P < 0.01; control subjects: 23.0 +/- 7.99%, P < 0.01; and KD subjects: -0.3 +/- 6.5%; NS). A reduction in renal vascular resistance in response to L-arginine was evident in KP and control subjects but not in KD patients.


CONCLUSIONS
L-Arginine vasodilatory response was successfully assessed with MR quantitative flow measurements. KP patients and control subjects, but not those with KD, showed a preserved L-arginine-induced vasodilation of the renal vasculature.
De Cobelli
Francesco
F
Department of Radiology, Università Vita e Salute-San Raffaele, San Raffaele Scientific Institute, Milan, Italy. francesco.decobelli@hsr.it
Fiorina
Paolo
P
Perseghin
Gianluca
G
Magnone
Marta
M
Venturini
Massimo
M
Zerbini
Gianpaolo
G
Zanello
Alessandro
A
Mazzolari
Gabriella
G
Monti
Lucilla
L
Di Carlo
Valerio
V
Secchi
Antonio
A
Del Maschio
Alessandro
A
D000328:Adult; D001120:Arginine; D001783:Blood Flow Velocity; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000503:physiopathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D007668:Kidney / Q000098:blood supply*; D016030:Kidney Transplantation; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D016035:Pancreas Transplantation; D012079:Renal Circulation; D014511:Uremia / Q000209:etiology / Q000503:physiopathology*; D014655:Vascular Resistance; D014664:Vasodilation
D001120:Arginine