Somatogen Inc. stock leaped $6.50 on Tuesday after thecompany said it has received Food and Drug Administrationpermission to begin human testing of its patented bloodsubstitute in a small number of volunteers.

The stock (NASDAQ:SMTG) closed at $40.50.

The Boulder, Colo., company's hemoglobin is designed toreplace blood lost in surgery or trauma, and would avoid therisk of contracting blood-borne infections such as hepatitisand AIDS through transfusion.

The preliminary clinical trial will check the safety and properdosage of rHb1.1, a recombinant protein that mimics humanhemoglobin while avoiding the problems that have plaguedattempts to develop blood substitutes.

The recombinant hemoglobin is stabilized by a single aminoacid, glycine, that bridges the four subunits of the molecule.Hemoglobin usually dissociates into dimers outside of redblood cells. These dimers are filtered by the kidneys, whichcould explain the renal toxicity seen with previous attempts todesign blood substitutes, Charles Scoggin, chief executiveofficer, told BioWorld. -- Roberta Friedman, Ph.D.

(c) 1997 American Health Consultants. All rights reserved.