PT  - JOURNAL ARTICLE
AU  - Avogaro, Angelo
AU  - Toffolo, Gianna
AU  - Kiwanuka, Edward
AU  - de Kreutzenberg, Saula Vigili
AU  - Tessari, Paolo
AU  - Cobelli, Claudio
TI  - <span class="sc">l</span>-Arginine-Nitric Oxide Kinetics in Normal and Type 2 Diabetic Subjects
AID  - 10.2337/diabetes.52.3.795
DP  - 2003 Mar 01
TA  - Diabetes
PG  - 795--802
VI  - 52
IP  - 3
4099  - http://diabetes.diabetesjournals.org/content/52/3/795.short
4100  - http://diabetes.diabetesjournals.org/content/52/3/795.full
SO  - Diabetes2003 Mar 01; 52
AB  - Defective endothelium is a key event in the development of atherosclerosis in diabetes: alteration of the l-arginine-nitric oxide (NO) pathway has been suggested. We propose a modeling approach of the l-arginine-NO pathway in vivo in both control and type 2 diabetic subjects based on the intravenous bolus injection of l-[15N]arginine and subsequent noncompartmental and compartmental model analysis of l-[15N] arginine in plasma and [15N]nitrate in the urine. No differences in arginine kinetics were observed between normal subjects and diabetic patients. [15N]nitrates were detectable up to 48 h from the l-15[N]arginine administration; no differences were found in the tracer-to-tracee ratio in each urine collection. However, the NO synthesis in plasma from arginine was lower (P = 0.05 for the noncompartmental and 0.1208 for the compartmental analysis, by Mann-Whitney test) in diabetic patients than in control subjects when expressed both in absolute terms (50% decrease) and as percentage of NO turnover (30% decrease). This new modeling approach of l-arginine-NO pathway provides a detailed picture of arginine kinetics and nitrate metabolism. From our data, it appears that noncomplicated type 2 diabetic patients have a decreased conversion of arginine to NO.