Stroma-free hemoglobin solutions prepared by crystallization and ultrafiltration methods; comparison of composition...

Stroma-free hemoglobin solutions (SFHS) were prepared by the crystallization and ultrafiltration methodologies. The preparations were partially characterized with respect to their effects upon the isolated perfused rat heart. SFHS prepared by ultrafiltration is characterized by a substantially lower content of residual membrane phospholipid and a more restricted protein composition. This preparation is also essentially free of vasoconstrictor and contractility-depressant actions on the ex vivo perfused heart. In contrast, crystallization-produced SFHS is less well purified of both phospholipid and protein constituents, is likely to generate denatured protein aggregates during storage and exhibits vasoconstrictor and contractility-depressant activity which may vary significantly, from batch to batch. These findings indicate that preparative methodology based on ultrafiltration and size-exclusion, yields SFHS which is superior in these respect to that produced by a crystallization method.