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Ex Vivo Red Blood Cell Hemolysis Assay for the Evaluation of pH-responsive Endosomolytic Agents for Cytosolic Delivery of Biomacromolecular Drugs
Published on: March 9, 2013
THE KINETICS OF IN VIVO HEMOLYTIC SYSTEMS.
1The Nassau Hospital, Mineola, Long Island.
The Journal of General Physiology
|October 30, 2009
Summary
This study explores in vivo hemolysis, examining lysins, accelerators, and inhibitors in blood. It proposes a steady-state model for red blood cell destruction and production, crucial for understanding hemolytic diseases.
Area of Science:
- Hematology and Immunology
- Biochemistry of hemolysis
- Physiology of red blood cell dynamics
Background:
- Hemolysis in vivo is a complex process involving red blood cell destruction.
- Understanding the balance between red blood cell production and destruction is key to maintaining a steady state.
- Various factors, including lysins, accelerators, and inhibitors, influence hemolytic activity.
Purpose of the Study:
- To investigate the mechanisms of in vivo hemolysis.
- To analyze the roles of lysins, accelerators, and inhibitors in hemolytic systems.
- To develop a model for the steady state of red blood cell turnover.
Main Methods:
- Analysis of additive effects of lysins, accelerators, and inhibitors using R-values.
- Confirmation of Maegraith, Findlay, and Martin's findings on tissue lysins, investigating species specificity.
- Quantification of plasma inhibitors, including cholesterol, proteins, and lecithin, and their contributions to hemolysis inhibition.
- Development of kinetic equations to model the steady state of red blood cell production and destruction.
Main Results:
- Effects of lysins, accelerators, and inhibitors are generally additive in simple systems.
- Normal intravascular lysins play a minor role unless concentrations are elevated or inhibitors are reduced.
- Identified three main in vivo hemolytic processes: bile salts/soaps, spleen action, and tissue-derived lysins.
- Tissue lysins are not exclusively species-specific; non-species-specific lytic substances, similar to lysolecithin, are also found.
- Plasma inhibitory effects are attributed to cholesterol (30%), proteins (25%), and synergistic interactions (45%), influenced by nutrition.
- Kinetic equations were developed to describe red blood cell count changes based on destruction rates.
Conclusions:
- In vivo hemolysis is regulated by a complex interplay of lysins, accelerators, and inhibitors within a dynamic steady state.
- Plasma's inhibitory capacity is multifactorial, involving cholesterol, proteins, and lecithin, and is sensitive to nutritional status.
- The developed kinetic model provides a framework for relating red blood cell levels to the intensity of hemolytic processes.
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