Platelet and Fibrinogen Reactions in <i>Pseudomonas aeruginos</i><i>a</i> Exotoxin Shock

Abstract

The distribution of radioactively labelled platelets, fibrinogen and erythrocytes in blood and various organs was studied after one injection of Pseudomonas aeruginosa exotoxin in dogs. The blood pressure often immediately dropped but then rapidly returned to the control level. This so-called anaphylactoid phase was followed by a progressive shock accompanied by decreasing blood pressure. The platelets also immediately decreased in the blood and appeared in the lungs during this anaphylactoid phase. Immediately after the injection there were also signs of platelet aggregation in the blood. These changes had a tendency to return to the control-value levels but did not fully reach these levels again. No further changes were observed in the blood or lungs during the shock phase. The changes are interpreted as a platelet aggregation induced by the exotoxin. Evidence of a fibrinogen consumption was found but there was no accumulation in any organ. The changes were not induced by the surgical trauma which was necessary to obtain organ biopsies. A similar behaviour of platelets and fibrinogen in blood was found in dogs not subjected to thoracotomy or laparotomy.

Serotonin in the lung. Demonstration of a close correlation to blood platelet

“…We have given consideration to the blood inclusion but by measuring the hemoglobin concentration in the tissue homogenate. Indeed, platelets have been shown to be entrapped by the lung after trauma [21], septic shock [22] and hemorrhagic shock [23], or during the in vitro pump perfusion of the lung [24] and acute respiratory failure [25][26][27]. The reported accumulation ofplatelets in the lung following the traumatic, septic and hemorrhagic shock was a slow process.…”

Pseudomonas aeruginosa exotoxin: purification by preparative polyacrylamide gel electrophoresis and the development of a highly specific antitoxin serum

“…Since the discovery of Pseudomonas aeruginosa exotoxin A by P. V. Liu (10), a number of studies have been made that suggest that the exotoxin greatly contributes to the virulence of the organism in a variety of animal models and tissue culture systems (1,2,6,8,12,(18)(19)(20). Several years ago it was found that P. aeruginosa exotoxin A (11), hereafter referred to as PA-toxin, inhibits protein synthesis in tissue cultures in vitro (19) and in mouse organs in vivo (20).…”

Cervical dislocation of mice induces rapid accumulation of platelet serotonin in the lung

“…Platelets in the capillaries, however, have not been counted. Platelets have been shown to be entrapped by the lung after trauma [12,13], septic shock [14,15], hemorrhagic shock [16], and acute respiratory failure [17][18][19][20]. Although the pulmonary accumulation of platelets after trauma is reportedly a slow process, the entrapment of platelets after cervical dislocation could have been caused, in part, by associated tissue injury, resulting in the formation in the lung capillaries of microthrombi [21,22].…”

“…The amount of 5HT measured in the lung seemed too high to be attributed to localization in the former two cell types described above. On the other hand, platelets are known to be entrapped by the lung after trauma [12,13], septic shock [14,15], hemorrhagic shock [16] and acute respiratory failute [17][18][19][20]. It is very possible that the high level of 5HT observed in the lung was due to the accumulation of platelets in that organ, but the localization of 5HT in lung tissue has not been determined.…”