L-Arginine Role for Stone Lower Ureter : A Randomized Control Study

Urolithiasis is a common disease worldwide and its incidence is growing [1]. Urinary stones are frequently located in the ureter and most ureteral stones are reported to be located distally [2]. Stones < 3 mm in diameter have a better chance to pass spontaneously in the majority of cases, whereas stones > 6 mm in the ureter are unlikely to pass in most situations [3].

Therefore, active watchful waiting forms one of the treatment options in some clinical scenarios.

Minimal invasive treatment strategies such as extracorporeal shockwave lithotripsy and ureteroscopy are frequently applied procedures in ureteral stone disease. However, indications for watchful waiting might be extended by the addition of so-called 'expulsive medical therapy'.

Nitric Oxide (NO) L -Arginine-derived NO is the major inhibitory NANC neurotransmitter in the lower urinary tract [4]. Neuronal NO synthase (NOS)-positive neuronal axons and nerve-ending-like structures have been detected in muscular layers of the human ureter suggesting that ureteral relaxation may involve the NO pathway [5]. NOS-reactive nerves have also been demonstrated immunohistochemically in the human intravesical ureter.

A recent study suggested that the L-arginine/NO/cyclic GMP pathway may play a role in the regulation of the valve function of the ureterovesical junction [6].