International seminar on nursing legislation July 6, - 16 1970. Warsaw, Poland.
Explore the source record for details and available documents.
International Cooperation↗
Biomedical subjects
J Symes
Publications and source records attributed to J Symes.
Adenosine enhances left ventricular flow during 24-hour hypothermic perfusion of isolated cardiac allografts.
Left ventricular flow progressively decreases during preservation of ex vivo hearts by continuous hypothermic perfusion, according to previous studies. This study was done to determine whether left ventricular flow could be maintained during 24-hour hypothermic perfusion by the addition of adenosine to the perfusate. Isolated canine hearts were perfused with either a modified Krebs-Henseleit solution or with the control solution containing adenosine (20 mumol/L) for either 4 or 24 hours. On completion of the perfusion period, radioactive microspheres were injected into the arterial inflow of the hearts. Myocardial samples were then taken from the endocardial, midcardial, and epicardial portions of the free wall and papillary muscles of the right and left ventricles, as well as the interventricular septum. Concentrations of radioactivity were determined for each sample, summed, and averaged for each ventricle. The ratio of average concentrations (L/R ratio) was significantly increased in the 24-hour adenosine hearts compared with 24-hour controls (1.10 +/- 0.15 vs 0.64 +/- 0.21, p less than 0.005). The L/R ratio of 4-hour controls (1.30 +/- 0.48) was also greater than that of 24-hour controls (p less than 0.005). These results suggest that left ventricular flow decreases during continuous hypothermic perfusion. The tendency toward diminished left ventricular perfusion after 24 hours is reduced when adenosine is added to the perfusate. Adenosine may be beneficial in ex vivo heart preservation with hypothermic perfusion by improving left ventricular flow.
Adenosine↗
Enhanced 24-hour in vitro heart preservation with adenosine and adenosine monophosphate.
Continuous hypothermic perfusion is an effective means of preserving ex vivo cardiac allografts. Using canine hearts, we assessed the ability of the high-energy phosphate precursors adenosine and adenosine monophosphate to enhance the protective effect of continuous hypothermic perfusion. Group 1 hearts (controls) were perfused for 24 hours with a modified Krebs-Henseleit solution. Group 2 hearts were perfused with control perfusate to which adenosine was added (20 mumol/L). Group 3 hearts were perfused with control perfusate with adenosine monophosphate (0.1 mmol/L). After perfusion heart weights increased similarly in all groups. Coronary vascular resistance increased during the preservation period in group 1 hearts, but decreased in groups 2 and 3 hearts. Developed pressures were 103 +/- 22 mm Hg in group 1, 163 +/- 27 mm Hg in group 2 (p less than 0.01), and 141 +/- 34 mm Hg (p less than 0.05) in group 3. The rate of pressure development in group 2 (2143 +/- 249 mm Hg) and group 3 (2059 +/- 395 mm Hg) hearts was significantly greater than in group 1 hearts (1434 +/- 363 mm Hg, p less than 0.01). Only group 3 myocardial adenosine triphosphate levels were significantly greater than controls (3.18 +/- 0.52 mumol/gm vs 2.12 +/- 0.74 mumol/gm, p less than 0.05) on completion of perfusion. Myocardial lactate levels at this time were significantly higher in group 1 hearts (7.48 +/- 3.96 mumol/gm) compared with groups 2 and 3 (0.34 +/- 0.58 mumol/gm and 1.50 +/- 0.91 mumol/gm, respectively, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Adenosine↗