Related Experiment Videos
Pseudomonal elastase injection causes low vascular resistant shock in guinea pigs
M M Khan1, T Yamamoto, H Araki
1Department of Molecular Pathology, Graduate School of Medical Sciences, Kumamoto University, Japan.
Biochimica Et Biophysica Acta
|August 4, 1993
Summary
Pseudomonas aeruginosa elastase, not endotoxin, causes septic shock by lowering blood pressure and increasing heart rate. This bacterial proteinase may be a key factor in human septic shock development.
Area of Science:
- Microbiology
- Pathophysiology
- Biochemistry
Background:
- Septic shock is a life-threatening condition often associated with bacterial infections.
- The role of specific bacterial virulence factors, such as enzymes, in the pathogenesis of septic shock requires further elucidation.
- Pseudomonas aeruginosa is a common opportunistic pathogen implicated in various infections.
Purpose of the Study:
- To investigate the role of Pseudomonas aeruginosa elastase in inducing septic shock.
- To differentiate the effects of elastase from endotoxin in causing cardio-respiratory collapse.
- To explore potential therapeutic interventions targeting bacterial elastase.
Main Methods:
- Administration of culture supernatants from elastase-producing and non-producing Pseudomonas aeruginosa strains to guinea pigs.
- Intravenous and intracardiac injection of purified Pseudomonas aeruginosa elastase and endotoxin.
- Assessment of hemodynamic parameters (mean arterial blood pressure, heart rate, respiratory rate, peripheral vascular resistance, cardiac output) in anesthetized and conscious animals (guinea pigs and rats).
- Evaluation of protective effects of anti-elastase antibodies and a synthetic elastase inhibitor.
Main Results:
- Culture supernatants from elastase-producing Pseudomonas aeruginosa induced significant hypotension, tachycardia, and tachypnea in guinea pigs.
- Purified Pseudomonas aeruginosa elastase, but not endotoxin, reproduced the shock-like state and mortality.
- Pretreatment with anti-elastase antibodies or a synthetic inhibitor abrogated the shock-inducing effects of elastase.
- Elastase administration led to decreased peripheral vascular resistance and cardiac output, consistent with low-resistant shock.
Conclusions:
- Pseudomonas aeruginosa elastase is a potent mediator of septic shock, distinct from the effects of endotoxin.
- Bacterial proteinases, specifically Pseudomonas aeruginosa elastase, may play a crucial role in the development of human septic shock.
- Targeting bacterial elastase presents a potential therapeutic strategy for managing septic shock.