[Possible consequence of ACTH-like peptides for human mental performance (author's transl)].

ACTH affects behavior of rats. The results of the reported experiments suggest that ACTH effects on conditioned behavior are the result of an improved motivation or attention. The ACTH fragments, ACTH 4--10 and ACTH 4--9, have the behavioral effects of ACTH but are devoid of endocrine activities. The ACTH 4--9 analog H-Met(O2)-Glu-His-Phe-D-Lys-Phe-OH (Org 2766) has behavioral activity after oral administration. ACTH-like-peptides restore the behavioral deficiencies of hypophysectomised rats and delay extinction of conditioned behavior of normal rats independent of the type of conditioning. So is extinction of pole jump avoidance and extinction of conditioned tast aversion delayed after Org 2766. Moreover ACTH-like peptides reduce the behavioral deficit in rats with amnesia even when the treatment is given two weeks after the induction of amnesia. In man the administration of a single dose of ACTH 4--10 on Org 2766 reduces the duration of lapses as well as the number of errors of volunteers in a continuous performance task. These and similar observations suggest that ACTH-like peptides may be of practical consequence for the therapy of patients with impairments of cognitive processes.