OPTIMIZATION OF CELL-CULTURE CONDITIONS FOR THE EVALUATION OF THE BIOLOGICAL-ACTIVITIES OF THE TETRAPEPTIDE N-ACETYL-SER-ASP-LYS-PRO, A NATURAL HEMOREGULATORY FACTOR

The present study attempts to define the difficulties in evaluating th e properties of the hemoregulatory peptide AcSDKP using in vitro assay s. In fact, in the presence of sera, which are generally added to basi c culture media, AcSDKP is catabolized by proteases present in the ser um. The kinetics of AcSDKP degradation depends on the nature and on th e concentration of the added serum. In in vitro conditions, the half l ife of this peptide can be increased by the addition of 1 muM captopri l, a metalloprotease inhibitor. Thus, these points need to be consider ed in designing experiments to study the effects of AcSDKP.