Abstract:

Objective     To observe the effects of shear stress on rat pulmonary microvascular endothelial cells (PMVECs) cultured in vitro and to elucidate the early pathogenesis of pulmonary hypertension induced by high pulmonary flow. Methods    Rat PMVECs were cultured with conventional methods. Self-made perfusion system was used to exert different shear stresses on rat PMVECs. The dynamic changes of F-actin stained by FITC-phalloidin were observed through laser scanning confocal microscope. Results   Microfilament rearrangement (compliant changed from former disorderliness into orderliness) occurred in PMVECs due to the shear stress, towards the direction of the shear force. Stress fibers appeared along the cell long axis. This change was time and stress strength dependent. With the extension of treatment time, the phenomena became more obvious， until nearly all the F-actin changed to be stress fibers.  ConclusionThe cytoskeleton of the PMVECs will rearrange to be stress fibers according to the shear stress it endured. This phenomenon is both time and stress strength dependent, and occurs at the early stage. This may be closely related to the early pathogenesis of pulmonary hypertension induced by high pulmonary flow.

Key words: Shear stress; Cytoskeleton; Pulmonary microvascular endothelial cells; Hypertension, pulmonary