Light-induced translocation of cyclic-GMP phosphodiesterase on rod disc membranes in rat retina.

Purpose: Cyclic GMP phosphodiesterase (PDE) is the light-regulated effector enzyme of vertebrate rods. Upon photo-activation of rhodopsin followed by activation of transducin/GTP, PDE rapidly hydrolyzes 3', 5'-cyclic GMP (cGMP) to 5'-GMP, which results in closure of cGMP-dependent ion channels and generation of a nerve signal. In the rod photoreceptors, PDE is entirely localized within the rod outer segment (ROS), a specialized compartment consisting of thousands of disc stacks.

The effects of additive solution pH and metabolic rejuvenation on anaerobic storage of red cells.

Background: Red cell (RBC) storage can be extended to 9 weeks under anaerobic or alkaline conditions. Simultaneous use of these approaches has not provided additive benefit. Our objective was to determine whether anaerobic storage with acidified additive solution (AS) coupled with metabolic rejuvenation might further improve the benefits of anaerobic storage.

Extended storage of red blood cells under anaerobic conditions.

Background: Red blood cells (RBC) are subject to oxidative stress by reactive oxygen species during refrigerated storage. Near-complete removal of oxygen from red cells during storage should eliminate this contributor to the red cell 'storage lesion'. The in vitro effects of storing red cells under oxygen-depleted conditions for extended periods were investigated, and these were correlated with the observed recoveries after reinfusion.

A detailed study of time-dependent changes in human red blood cells: from reticulocyte maturation to erythrocyte senescence.

The use of microfabrication technology in the study of biological systems continues to grow rapidly in both prevalence and ascendancy. Customised microdevices that provide superior results than traditional macroscopic methods can be designed in order to investigate specific cell types and cellular processes. This study showed the benefit of this approach in precisely characterising the progressive losses of surface area and haemoglobin (Hb) content by the human red blood cell (RBC), from newborn reticulocyte to senescent erythrocyte.

Direct measurement of the impact of impaired erythrocyte deformability on microvascular network perfusion in a microfluidic device.

The ability of red blood cells (RBCs, erythrocytes) to deform and pass through capillaries is essential for continual flow of blood in the microvasculature, which ensures an adequate supply of oxygen and nutrients, prompt removal of metabolic waste products, transport of drugs and hormones, and traffic of circulating cells to and from all living tissues. This paper presents a novel tool for evaluating the impact of impaired deformability of RBCs on the flow of blood in the microvasculature by directly measuring perfusion of a test microchannel network with dimensions and topology similar to the real microcirculation. The measurement of microchannel network perfusion is compared with RBC filtration -- a conventional assay of RBC deformability.