Journal of Membrane Science & Technology

Mechanisms of RBC Rheologic Alterations in Sepsis and their Impact on Blood Flow

Michael Biston^* Department of Intensive Care, CHU-Charleroi, Vrije Universiteit Brussel, Belgium
^*Correspondence: Michael Biston, Department of Intensive Care, CHU-Charleroi, Vrije Universiteit Brussel, Belgium, Email:

Received: 23-Dec-2022, Manuscript No. JMST-23-20070; Editor assigned: 27-Dec-2022, Pre QC No. JMST-23-20070 (PQ); Reviewed: 09-Jan-2023, QC No. JMST-23-20070; Revised: 17-Jan-2023, Manuscript No. JMST-23-20070 (R); Published: 23-Jan-2023, DOI: 10.35248/2155-9589.23.13.323

Description

Erythrocytes have traditionally been thought of as "dead" cells that solely transport Oxygen (O₂). Red Blood Cells (RBCs) capacity to control the microcirculation is now determined as crucial supplementary function. This membrane composes of bloodstream, endothelium, and other blood cells on one hand, and the intracytoplasmic compartment with a potential for rapid adaptation of erythrocyte metabolism on the other hand, which is a complex unit with multiple interactions between the extracellular and intracellular compartments. To lessen morbidity and mortality from severe sepsis, it may be helpful to understand the mechanisms underlying RBC rheologic abnormalities in sepsis and their consequences on blood flow and oxygen delivery. The microcirculation, which consists of all blood vessels with a diameter of less than 100 m, blood cells (such as red blood cells, white blood cells, and platelets), endothelium, and microparticles, is vital for the oxygenation of tissues as oxygen (O₂) diffuses from blood to the cells in each tissue across the walls of the microvessels. Critically ill individuals typically exhibit changes at this level of the circulatory system, especially those who have sepsis, and the persistence of these changes is linked to poor prognosis.

The membrane of RBCs was once thought to be just a plain container for the crucial cytoplasmic protein hemoglobin. Together with cell shape and cytoplasmic viscosity, the membrane is one of the primary determinants of RBC deformability. The composition of various membrane constituents are lipids, which make up 50% of the membrane's molecular weight; proteins, which make up 40%; and carbohydrates, which make up 10%. Any of these elements may change in sepsis, either directly as a result of bacterial action or indirectly through the action of enzymes and/or Reactive Oxygen Species (ROS) produced by WBCs and/or platelets. However, few studies, have examined sepsis-related membrane changes. It's interesting that a number of recent studies have indicated that the RBC plays a significant role in controlling the microcirculation. For these reasons, RBCs are considered as “live cells” capable of altering the microcirculation in response to varied stimuli, rather than “dead cells” without a nucleus and only a membrane and haemoglobin to carry O₂ and CO₂.

The RBC membrane is observed as a key component of RBC rheology, particularly in terms of deformability. Its molecular weight is made up of proteins (52%), lipids (30%), and carbohydrates (8%), which interact with one another in intricate ways. RBC rheology and probably RBC biochemistry could also change as a result of modifications to RBC membrane components. There aren't many studies that look at how sepsis affects the protein portion of the RBC membrane. Yet, in hypoxic conditions, the RBC membrane takes part in the creation of ROS. During sepsis, the lipid layer of the human RBC membrane may change and the RBC membrane's lipid peroxidation appears to be accelerated in sepsis. Just 8% of the molecular weight of the human RBC membrane is made up of carbohydrates, making them a modest component of the RBC membrane. The glycolipid and integral glycoprotein carbohydrate domains make up the majority of the RBC glycocalyx. Together with neutral hexoses, pentoses, and N-acetylhexosamines, these oligosaccharides also include fully ionised sialic acid. About 40 naturally occurring 9-carbon keto sugar acids produced from Nacetylneuraminic acid (Neu5AC) are collectively referred to as sialic acid (sialon in Greek, meaning saliva). N-acetylneuraminic acid is the Sialic Acid (SA) derivative that is most prevalent in humans and RBCs.

Conclusion

The most significant transmembrane protein, glycophorin A, is heavily glycosylated, with over 60% of its weight being made up of carbs. The majority of the carbohydrates are composed of 15 tetrasaccharides that are O-glycosidically connected. According to the species, the two SA residues of each of these numerous Oglycosidically connected oligosaccharides account for 60% to 90% of the negative charge on the RBC membrane surface, which explains why RBCs often resist one another and do not merge. Research on RBC rheology and the microcirculation in septic patients is rare. Sepsis causes modifications to RBC membrane components, which may be a factor in the reported changes in RBC rheology. A deeper comprehension of these mechanisms may lead to the development of methods for enhancing RBC rheology and, consequently, the microcirculation in patients.