Lack of protective effect of adrenaline tolerance haemorrhagic shock in conscious dogs.

Dogs were made tolerant to lethal doses of adrenaline by treatment with increasing doses of the hormone up to 1 mg/kg. The conscious animals were then subjected to haemorrhagic shock with a hypovolaemic period of 3 hours. Survival was 8/17 in the pretreated group and 15/18 in the control group. 12 of 29 dogs died already during adrenaline treatment. Plasma catecholamine levels were higher in the treated group already before bleeding and also during hypovolaemia. Catecholamine induced myocardial lesions were found in the treated group. No evidence of a blunting of the sympathetic response or a protective effect in haemorrhagic shock was seen in adrenaline tolerance.