Isolated pig hearts (German farm pigs) were characterized after global in-vivo ischaemia as a potential alternative to in-vivo animal studies. Hearts were harvested from adult farm swine at the abattoir 10.3 +/- 2.1 min after incision of the carotid artery. They were immediately perfused and thereafter stored in ice-cold cardioplegic (St Thomas's) solution. After 38 +/- 3 min, retrograde perfusion was started with oxygenated pig blood (37 degrees C; 5000 U Heparin.l-1; pH 7.38 +/- 0.1; 11 mmol glucose.l-1) at a flow rate of 85 ml.min-1 100 g-1 wet weight (gww-1) for 30 min (n = 10). Additionally, shortly after obtaining the hearts, ATP and CP content were measured by enzymatic tests in 10 pigs at the beginning and after 15 and 30 min of reperfusion. Heart rate was 90 +/- 14 min-1 with little variation during 30 min. Perfusion pressure increased from 89 +/- 17 mmHg to 100 +/- 17 mmHg (NS). Wet weight rose from 488 +/- 33 to 548 +/- 45 g (P < 0.002). CK increased from 2180 +/- 558 to 5900 +/- 1018 U.l-1 (P < 0.001). Calcium in the perfusate decreased from 2.45 +/- 0.15 to 2.2 +/- 0.25 mmol.l-1 and magnesium increased from 0.85 +/- 0.2 to 1.79 +/- 0.35 mmol.l-1 (both P < 0.001). The transmural ATP and CP content was 2.8 +/- 0.48 and 5.08 +/- 0.88 mumol.gww-1.ATP fell moderately during reperfusion to 2.6 +/- 0.35 mumol (NS) and CP rose to 6.0 +/- 1.2 mumol (P < 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)