CLINICAL AND MANOMETRIC EFFECTS OF L-ARGININE IN PATIENTS WITH CHEST PAIN AND ESOPHAGEAL MOTOR DISORDERS

Background/Aims. Nitroderivatives are therapeutically effective in spa stic disorders of the oesophagus through the generation of nitric oxid e, a non-adrenergic non-cholinergic inhibitory neurotransmitter, but t heir use is limited by undesirable side effects and rapid appearance o f drug tolerance. As nitric oxide ''in vivo'' is generated from L-argi nine, an aminoacid normally present in the diet and completely devoid of toxic effects, we administered the latter substance in patients wit h chest pain and oesophageal motor disorders of the spastic type to in vestigate if it is able to produce clinical and manometric effects sim ilar to those manifested by nitroderivatives. Methods. In eight patien ts affected by non cardiac chest pain and oesophageal motor disorders of a hypertonic-hyperkinetic type without pathologic gastro-oesophagea l reflux, a solution containing L-arginine and a placebo solution were infused in random order and double blind manner during a manometric e xamination of the oesophagus, taking into account the spontaneous vari ations of oesophageal motility connected with the phases of the Migrat ing Motor Complex. Afterwards, in the same patients a solution contain ing L-arginine and a placebo solution were administered orally, in ran dom order and double blind manner each for a period of six weeks. The effect of each treatment on frequency and intensity of chest pain atta cks and on nitroderivatives intake was recorded on a diary by the pati ents. Results and Conclusions. The intravenous administration oft argi nine did not show the typical inhibitory effect of nitroderivatives on lower oesophageal sphincter tone and on amplitude and duration of pre ssure waves, but the chronic oral intake of L-arginine significantly d ecreased the frequency and intensity of chest pain attacks, as well as the number of nitroderivative tablets taken for analgesic purposes, t hus suggesting a possible therapeutic role of this substance in this k ind of patient.