[Cellular signalling pathways and pathophysiology of pulmonary arterial hypertension]

Pulmonary arterial hypertension (PAH) is a disease of complex aetiology involving in varying degrees both genetic and environmental factors.

Thanks to progress in biology over the past 15 years the physiological consequences of cellular and molecular abnormalities are much better understood. Recent work has allowed better understanding of the different cellular signalling pathways controlling pulmonary vascular tone and cell growth. It appears that these pathways form a dense and complex network involving several groups of molecules of which NO, cGMP, ET-1 and its receptors, are at the most important.

The pathophysiology of PAH may be regarded as a disorder of cellular signaling where molecular abnormalities disturb the balance between the different factors controlling vascular tone and cell proliferation.

PAH may be viewed as a disease of cellular signalling where the molecular abnormalities not only affect a single signalling pathway but involve multiple cross-talks between groups of molecules controlling vascular smooth muscle tone and cell growth and differentiation.