COMPARISON OF THE EFFECTS OF ACTH-(1-24), METHYLPREDNISOLONE, APROTININ, AND NOREPINEPHRINE IN A MODEL OF HEMORRHAGIC-SHOCK IN RATS

Rats bled to a severe condition of volume-controlled hemorrhagic shock were randomly assigned to one of the following treatments: (1) saline , 1 ml/kg i.v.; (2) saline, 0.2 ml/kg per min i.v. for 10 min; (3) ACT H-(1-24),160 mug/kg i.v.; 4) methylprednisolone, 40 mg/kg i.v.; (5) me thylprednisolone, 80 mg/kg i.v.; (6) aprotinin, 10 000 KIU/kg i.v.; (7 ) norepinephrine, 5 mug/kg per min i.v. for 10 min; (8) norepinephrine , 10 mug/kg per min i.v. for 10 min. All rats treated with saline or w ith either of the two doses of methylprednisolone, and half of the rat s treated with aprotinin, died within the subsequent 2 h. On the other hand, rats treated with norepinephrine, at either dose, or with ACTH- (1-24) were all still alive 2 h later, a similar improvement in cardio vascular and respiratory parameters being obtained with the two treatm ents. The effect of ACTH on mean arterial pressure was however more su stained throughout the observation period. These results further suppo rt the potential usefulness of ACTH-(1-24) as first-aid treatment in c ases of severe blood losses.