The invention relates to compositions suitable for plasma substitution
comprising as a plasma expander a recombinant gelatin-like protein.
Characteristic is that the gelatin-like protein can be a monomer or a
polymer like a dimer, trimer or a tetramer of a human recombinant
gelatin-like protein having an isolectric point of less than 8. The
resulting gelatin-like proteins provide a method to control the clearance
rate of a plasma expander by its molecular weight. Preferably the
gelatin-like proteins have a low hydroxyproline content which prevents
the composition from gelling and thus allows the use of high-molecular
weight proteins in order to establish a suitable colloid osmotic
pressure. An additional advantage of the gelatin-like proteins is that
these avoid the risk of anaphylactic shock that exists in conjunction
with the use of commercially available preparations.