Simultaneous determination of serum concentrations of levodopa, dopamine, 3-O-methyldopa and alpha-methyldopa by HPLC.

Levodopa is the medication of choice for Parkinson's disease. The biological complexity of levodopa and of its main derivatives makes their determination important in the clinical field. The aim of this study was to develop an HPLC method for the simultaneous determination of serum concentrations of levodopa, dopamine, 3-O-methyldopa and alpha-methyldopa.

Nitric oxide levels in patients with atheromatous carotid plaque.

Nitric oxide (NO), an unstable derived of nitrogen, is released by endothelium in response to physiological stimulus. Indeed, the endothelium is not only a barrier between the lumen and the inner side of the vessel wall but also a metabolically active organ with endocrine, paracrine and autocrine functions. Endothelial vascular cells play an important role in the regulating vasomotor tone, local homeostasis and vascular bed proliferation.