Year: 1977
Type: conference-paper
Abstract: The frogs, unlike mammals, are extremely resistant to the lethal effect of gram-negative endotoxins. Even injecting enormous doses we were unable to determine the DL50 value at their usual ambient temperature. The finding by Levin and Bang that endotoxin activates the coagulation in the invertebrate Limulus suggested, however, a similar effect in frogs as well. Frogs were, therefore, injected with a high dose of E. coli Olll endotoxin (Boivin). Four hours later the fibrinogen level was 30 %, the thrombocyte count 50 %, and the neutrophil count 70% lower than the initial value. By 24 hours a further drop of fibrinogen level appeared, whereas the thrombocyte and neutrophil counts started to normalize. At that time, repeating the endotoxin injection (generalized Shwartzman reaction) a decrease of all 3 parameters studied was again observable in 4 hours. When frogs were treated i.p. with high endotoxin doses 72: 72 and 48; or 72, 48 and 24 hours before blood sampling, progressively prolonged prothrombin (Quick) and thrombin times were obtained, indicating a consumption coagulopathy. (Unfortunately, reptilase times are hardly measurable in frog plasma- Blut 30: 233, 1975) Also, abnormal clotting times were found when according to the previous schedule protamine HCl, known to exert multiple effects on the coagulation system, was given frogs (50 mg/100 g). The results show that endotoxin is able to trigger, like in mammals and Limulus, the clotting mechanism in frog.
Source: Thrombosis and Haemostasis
Institution: University of Debrecen
Language: English
Subfield: Hematology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2944906965