Oral arginine reduces systemic blood pressure in type 2 diabetes: its potential role in nitric oxide generation.

Arginine is converted in the endothelial cells to nitric oxide (NO) and citrulline. NO is a potent vasodilator in humans, but diabetics may have a reduced generation of NO which results in endothelial dysfunction. The aim of this study was to evaluate the effects of oral arginine on nitric oxide production, counter-regulatory hormones and blood pressure in mildly hypertensive type 2 diabetic patients.

A prospective, crossover clinical trial was performed over a three-day stay in the General Clinical Research Center. Six patients with type 2 diabetes mellitus and mild hypertension consented and were given orally three grams of arginine per hour for 10 hours on either day 2 or day 3. On both days 2 and 3, blood pressure was monitored between 5 AM and 4 PM and mean pressure determined.

Oral arginine increased plasma citrulline from 31.3 +/- 6.0 to 41.5 +/- 6.0 micro mol/L (mean +/- SEM; p < 0.05) which may reflect an increased conversion of arginine into NO and citrulline. Arginine reduced systolic BP from 135 +/- 7 to 123 +/- 8 mmHg; p < 0.05. Diastolic BP fell from 86.9 +/- 1.7 to 80.7 +/- 2.4 mmHg; p < 0.05). The reduction in BP was noted to occur two hours after starting oral arginine, and BP returned to normal within one hour of stopping the arginine. The oral arginine had no effect on C-peptide, insulin or other hormone concentrations.

These data suggest that oral arginine may increase endothelial nitric oxide synthase (NOS) to increase vascular NO and temporally reduce blood pressure in mildly hypertensive type 2 diabetic patients.

「経口アルギニンは2型糖尿病において全身血圧を低下させる:一酸化窒素生成におけるその潜在的な役割 」



経口アルギニンは、血漿シトルリンを31.3 +/- 6.0から41.5 +/- 6.0マイクロモル/L(平均+/- SEM;p < 0.05)に増加させ、これはアルギニンのNOとシトルリンへの変換の増加を反映している可能性がある。アルギニンは、収縮期BPを135+/-7から123+/-8 mmHgに低下させた(p < 0.05)。拡張期BPは86.9+/-1.7から80.7+/-2.4 mmHgに低下した(p < 0.05)。BPは、経口アルギニン投与を開始してから2時間後に減少することが認められ、アルギニン投与中止から1時間以内に正常に戻った。経口アルギニンは、C-ペプチド、インスリン、または他のホルモン濃度に影響を及ぼさなかった。