Essais de prevention et traitement du mal des rayons chez le poussin

Abstract

Rhode Island chicks aged 19 to 21 days are exposed to X-rays. If they receive a total dose of 2000 r (at a rate of 100 r/min), most of the deaths occur within the first 48 hours. There are two phases of lethality, one rapid and the other delayed. Among radio-protective substances which are very effective in the mouse and rat (cysteamine, cystamine, cysteine, tryptamine, sodium diethyldithiocarbamate, ethylenediaminotetracetic acid, sodium cyanide) only sodium diethyldithiocarbamate and tryptamine are feebly active in the chick; the former affects both lethality phases, the latter reduces only the delayed mortality. It is unlikely that they act by anoxia. The functional and metabolic disturbances resulting from irradiation are serious and appear promptly in fowls (circulatory breakdown, liberation of histamine, hyperkaliemia). Preliminary depletion of histamine reserves in the tissues by means of peptone and 48/80 reduces the number of early deaths without altering the delayed mortality rate. Of the anti-histamines studied, Neoantergan alone has a radioprotective action. This is appreciable in both lethality phases. When administered with curative intent, it becomes ineffective. Treatments aiming at correcting hyperkaliemia, palliating a subsequent cortico-surrenal deficiency or fighting infection have been without result.