Vaso-active Drugs and the Occurrence of Intra-muscular Ecchymotic Haemorrhages in the Electrically Stunned Rat

Intra-muscular ecchymotic haemorrhages were produced in rats by the repeated application of a 110 volt 50 Hz alternating current immediately prior to dislocation of the neck. Histological examination of these haemorrhages indicated that they were similar to those seen in meat animals slaughtered at abattoirs. The injection of a β-adrenergic blocking drug, propranolol, caused a reduction in the extent of the haemorrhages while the injection of an α-adrenergic blocking drug, phentolamine, increased their extent. It is postulated that an increase in mean capillary blood pressure, as a result of arteriolar dilatation, is one of the factors involved in the production of ecchymoses.