Changes of internal temperature and locomotor activity under the conditions of endotoxin fever, pyrogenic tolerance and its suppression in pigeons.

摘要

The aim of the study was to investigate changes of internal temperature and locomotor activity of birds in conditions of endotoxin fever, pyrogenic tolerance and its suppression. The experiment was performed in pigeons (n=12). On the first day of the experiment a state of endotoxin fever was evoked. The pigeons were categorized into two groups: experimental and control. The first group of the animals (n=8) received Escherichia coli LPS intravenously once at the dose of 10 micro g/kg b.w. whereas the control pigeons (n=4) were administered in the apyrogenic saline intravenously once at the dose of 1 ml/kg b.w. On the second and third day of the experiment the state of pyrogenic tolerance was induced in the pigeons and their internal temperature and locomotor activity were investigated. To this end the experimental group of birds received E. coli LPS intravenously twice at 24 h intervals at a dose of 10 micro g/kg b.w. Conversely, the control pigeons were twice treated with saline (1 ml/kg b.w.). On the fourth day of the study an attempt of pyrogenic tolerance suppression in the pigeons was carried out. The experimental birds with the stable state of pyrogenic tolerance were then categorized into two subgroups. The first subgroup (n=4) received Salmonella Abortusequi LPS intravenously at the dose of 10 micro g/kg b.w., whereas the second one (n=4) - E. coli LPS at a double amount of the pyrogen (20 micro g/kg b.w.). The control pigeons were administered S. Abortusequi LPS in an analogical dose as the first experimental subgroup. Results of the study indicated the occurrence of endotoxin fever and depression of locomotor activity of the pigeons in response to the first injection of E. coli LPS. The third administration of the pyrogen stabilized the state of pyrogenic tolerance, manifested by the reduction of the increased internal temperature and the stimulation of pigeon locomotor activity. Whereas in the state of stable pyrogenic tolerance in pigeons the intravenous injection of the other exogenous pyrogen, i.e. S. Abortusequi LPS, and also the double dose of E. coli pyrogen caused the suppression of the tolerance and the restoration of endotoxin fever in the birds.