Intraventricular antipyretics and bacterial pyrogen fever

In adult fowls with cannulae chronically implanted into the IIIrd cerebral ventricle or into the hypothalamus, the effects of various hydrosoluble antipyretics, given intraventricularly, on bacterial pyrogen fever were studied. It has been shown that fever evoked by intrahypothalamic or intraventricular infusion of O somatic antigen of Shigella Dysenteriae was reduced by intraventricular administration of acetylsalicylate-lysine, indomethacin-methylglucamine or ibuprofen-lysine given during the febrile plateau. However, a 3-day intraventricular pretreatment with acetylsalicylate or indomethacin, or a single administration 30 min before, did not prevent fever by subsequent intraventricular or intrahypothalamic injection of pyrogen. On the contrary, intraventricular infusion of indomethacin or acetylsalicylate substantially reduced pyrogen fever when given after pyrogen latency period, e.g. just at the beginning of the febrile response. A possible involvement of E prostaglandins as mediator to pyrogen fever is discussed.