The invention relates to the use of alpha 1-antichymotrypsin (ACT) polypeptides according to SEQ ID No. 1 to SEQ ID No. 4 and/or nucleic acids encoding them, or an antibody or a fragment thereof directed against the polypeptide, or of a cell which is expressing the polypeptide or a nucleic acid encoding it, for diagnosis, treatment and/or prevention of diabetes-associated and/or arterial wounds which heal poorly and for identifying pharmacologically active substances which exert an influence on the expression or function, particularly the activity of ACT.