Ultrastructural morphometric examinations on the protection provided by prostacyclin against myocardial ischaemia

Myocardial ischaemia in the dog lasting for three hours is followed by swellings of the mitochondria and dilatation of the sarcoplasmic reticulum. The volume density (Vv) of mitochondria in the peripheral ischaemia zone is 0.2890, that of sarcoplasmic reticulum is 0.0101. Prostacyclin was administered either i.v. or by triggering in conjunction with an intra-aortic balloon pump which led to an increase in the volume density of the mitochondria, mainly as a result of an increase in the volume of average mitochondria. The dilatation of the sarcoplasmic reticulum is reversed. It was not possible to prove in our investigations that prostacyclin provides protection against myocardial ischaemia.