L-arginine increases nitric oxide and attenuates pressor and heart rate responses to change in posture in sickle cell anemia subjects

Pressor and heart rate changes following change in posture without or with L-arginine supplementation (1g/day for 6 weeks) were studied in 28 sickle cell anemia (SCA) and 32 non-sickle cell anemia (NSCA) subjects. Change in posture increased HR (p<0.01), RPP (p<0.05) in both groups of subjects, MABP (p<0.05) in SCAS but reduced MABP (p<0.01) in NSCAS and PP (p<0.01) in SCAS. L-Arginine supplementation increased plasma L-Arginine concentration ([R]) in both groups of subjects (p<0.001 in each group) and serum nitric oxide metabolites concentration ([NOx]) (p<0.01 in each group). Change (Δ) [R] correlated positively with Δ [NOx] in both groups (+ 0.7 in each group). L-Arginine supplementation caused greater reduction of MABP (p<0.001) in NSCAS than in SCAS. However, reduction in HR was greater (p