Slaughterhouse blood as a perfusate for studying myocardial function under ischemic conditions

Abstract

Metabolic studies using the in vitro non-recirculating blood-perfused isolated heart model require large volumes of blood. The present study was designed to determine whether heterologous pig blood collected from a slaughterhouse can be used as perfusate for isolated pig hearts perfused under aerobic and constant reduced flow conditions. Eight isolated working pig hearts perfused for 90 min at a constant flow of 1.5 ml g -1 min -1 with non-recirculated blood diluted with KrebsHenseleit bicarbonate buffer at a hematocrit of 23% were compared to eight hearts subjected to the same protocol but perfused only with Krebs-Henseleit bicarbonate buffer solution. Hearts were paced at 100 bpm and subjected to aerobic perfusion at 38ºC. Hearts were weighed before perfusion and at the end of the experiment and the results are reported as percent weight gain (mean ± SD). Comparisons between groups were performed by the Student t-test (P<0.05). After 90 min of perfusion with modified Krebs-Henseleit, perfused hearts presented a larger weight gain than blood-perfused hearts (39.34 ± 9.27 vs 23.13 ± 5.42%, P = 0.003). Left ventricular end-diastolic pressure was higher in the modified Krebs-Henseleit-perfused group than in the blood group (2.8 ± 0.4 vs 2.3 ± 0.3 mmHg, respectively, P = 0.01). We conclude that heterologous blood perfusion, by preserving a more physiological myocardial water content, is a better perfusion fluid than modified Krebs-Henseleit solution for quantitative studies of myocardial metabolism and heart function under ischemic conditions.

Effects of long-term extracorporeal blood perfusion of the distal portion of isolated equine forelimbs on metabolic variables and morphology of laminar tissue

“…The constant amount of the oxygen consumption with no significant differences over time is also an indication for a good-quality oxygenation of the tissue and the viability of cells. 35,37 During forelimb perfusions, a significantly greater decrease in glucose concentration in the perfusate was found, compared with that of control perfusions. The difference between the glucose consumption during forelimb perfusion and the decrease in glucose as the result of blood cell metabolism during control perfusion was regarded as mean net glucose consumption of the tissues within the isolated perfused forelimbs (116.7 mg/h).…”