PRESERVATION OF CELL ORGANELLES DURING STORAGE OF HUMAN ATRIAL TISSUEIN THE UNIVERSITY-OF-WISCONSIN SOLUTION

Aim of the study. The University of Wisconsin storage solution (UW) (E .I. du Pont de Nemours, Wilmington, DE) has been successful in extendi ng the storage period using some model systems of donor heart preserva tion for cardiac transplantation. The ability of UW to preserve human cardiac cell organelle (sarcoplasmic reticulum, mitochondria and sarco lemmal) membrane composition (enzyme activity, protein, cholesterol an d phospholipid content) was compared to St, Thomas's Hospital Solution (ST) and saline. Methods. Human atrial appendages were stored at 4 de grees C for 24 h in saline, ST or UW or not stored (controls) and the cell organelles isolated, Each fraction was assayed for enzyme activit y (mitochondria: azide sensitive Ca2+ APTase, cytochrome C oxidase; sa rcolemmal membrane: Na+K+ ATPase, p-nitrophenylphosphatase; sarcoplasm ic reticulum: Ca2+ uptake, Ca2+ ATPase, NADPH cytochrome C reductase), protein, cholesterol and phospholipid content. Results. ''Protein yie ld'' proved to be the most sensitive marker for cell organelle preserv ation. Only the sarcolemmal membrane showed no decrease in either enzy me activities or ''protein yield'' after storage in saline, ST or UW, Mitochondria showed no decrease in enzyme activities but a decrease in . ''protein yield'' after storage in all 3 solutions, The ''protein yi eld'' of sarcoplasmic reticulum was significantly reduced after storag e in UW, saline and ST. No correlation could be drawn between choleste rol and phospholipid content and the preservation of cell organelle fu nction. Conclusions. It is possible to distinguish between the ability of solutions to preserve the membrane composition of human cardiac ti ssue during hypothermic storage, Using simple assays to assess preserv ation provides preliminary screening for a superior solution which can then be used in more complicated transplantation models to more fully assess cardiac function.