The effects of myocardial ischemia followed by reperfusion on perfused coronary capillarity.

To determine the effects of ischemia and reperfusion on myocardial perfused capillary density, rat hearts were excised, kept ischemic for thirty minutes then reperfused with blood from a support animal. Control hearts were isolated and perfused for either 10 or 60 minutes before injection of a vascular marker (Monastral Blue-blood mixture, 30 sec at 100 mmHg). The ischemic hearts were perfused with Blue after 10 minutes of reperfusion.

Role of procaine and washed red cells in the isolated dog heart perfused at 5 degrees C.

Isolated dog hearts were perfused for 24 hours at 5 degrees C with one of three solutions: plain Krebs solution, Krebs solution containing 167 mg/L of procaine hydrochloride, or Krebs-procaine solution with washed red cells (hematocrit 2%). Coronary vascular resistance (CVR) of hearts perfused with Krebs solution alone increased sharply between the eighth and the twelfth hours of perfusion and then stabilized. Increase of myocardial firmness paralleled the increase of CVR.

Protection by plasma proteins of the isolated lamb heart perfused with stroma-free hemoglobin at 38 degrees.

Isolated lamb hearts were perfused for eight hours at 38 degrees with stroma-free hemoglobin solution (SFHS). The preservation of cardiac structure and function was studied. Control hearts perfused with blood (N = 6) developed no ventricular failure or significant weight gain (13% +/- 5), showed no alteration of cellular ultrastructure, and little interstitial edema.

The Ito "Flow-Through" Centrifuge. A new device for long-term (24 hours) plasmapheresis without platelet deterioration.

An efficacious procedure for continuous plasmapheresis in long-term extracorporeal circulation has not yet been devleoped. This technique could be important in plasma exchange or cross-exchange and in artificial organ support if it could be accomplished safely using heparin as the anticoagulant. When sheep were connected to the Celltrifuge for 23 hours and administered 150 units/kg per hour heparin anticoagulant, we found gross platelet clumping in separated plasma and a 60 per cent fall in platelet count.

Fresh platelet-rich plasma from a flow-through centrifuge for lamb heart perfusion at 13degrees C. Protective effect of added erythrocytes.

Isolated lamb hearts perfused at 13degrees C. with acellular perfusates developed progressive intersitital edema and a rise in vascular resistance. They did not exhbit any electrical or mechanical activity.

New flow-through centrifuge without rotating seals applied to plasmapheresis.

The flow-through centrifuge eliminates complications arising from rotating seals. Preliminary studies on plasmapheresis demonstrated negligible platelet injury and no evidence of hemolysis during 12 hours of operation. Thus the system may provide a broad application to cell washing and elutriation, zonal centrifugation, and countercurrent chromatography.