EXPERIMENTAL FEVER IN SYMPATHECTOMIZED ANIMALS

Abstract

The intraven. injection of typhoid-paratyphoid vaccine in normal cats caused a febrile reaction, rapid in onset, with a max. increase of body temp, within 1-2 hrs. The fever curves show 2 distinct peaks, (1) within 1-2 hrs. after the injection, and (2) within 3-4 hrs. Sympathectomized cats show a delay both in the onset of the febrile reaction and in the attainment of the max. temp, increase. The fever curves are without clear-cut peaks. Similar results, except for the persistence of a slight first peak in the fever curve, are obtained from cats which have undergone ablation of the sympathetic outflow to the periphery ofthe body (splanchnic outflow intact). Fever curves of cats with splanchnic nerves sectioned or with adrenals inactivated are similar to those from normal animals except for a small delay in the onset of the reaction and in the attainment of the max. temp.; also, the first peak is much smaller after splanchnic section. A greater increase of body temp. is usually obtained in the normal than in the operated animals after vaccine injection. Fever can develop in sympathectomized cats in the absence of detectable shivering.