Compounds of the formula I, in which I 1, I 2, I 3, I 4, I 5, independently of one another, are N or CR', T is a phenyl, biphenyl or naphthyl which is unsubstituted or mono-, di, tri- or tetrasubstituted by R, or a mono- or bicyclic saturated, unsaturated or aromatic heterocycle having 1 to 4 N, O and/or S atoms, which may be mono-, di- or trisubstituted by R, =S, =NR' and/or =O, R 1 is isopropyl, 2-butyl or isobutyl, R 2 is n-propyl, isopropyl, 2-butyl or isobutyl, A 1 is leucine or a single bond, A 2 is valine, n is 0, Y is OH or O-benzyl, m is 1, L 1 is -(C=O)-, X is a linear or branched alkyl having 1-10 C atoms or cyclic alkyl having 3-10 C atoms, in which one, two or three CH 2 groups may be replaced, independently of one another, by O and which is unsubstituted or mono- or disubstituted by T, L 2 is a single bond, R,R', independently of one another, are H, linear or branched alkyl having 1-10 C atoms, in which one, two or three CH 2 groups may be replaced, independently of one another, by O, S, SO, SO 2, NH, NCH 3, -OCO-, -NHCONH-, -NHCO-, - NRSO 2 A-, -COO-, -CONH-, -NCH 3 CO-, -CONCH 3 -, -C≡C- groups and/or by -CH=CH- groups and/or, in addition, 1-20 H atoms may be replaced by F and/or C and which is unsubstituted or mono-, di- or trisubstituted by =S, =NR, =O, Hal, OH, NH 2, SO 2 CH 3, SO 2 NH 2, CN, CONH 2, NHCOCH 3 and/or NHCONH 2, or cyclic alkyl having 3-7 C atoms, in which one, two or three CH 2 groups may be replaced, independently of one another, by O, S, SO, SO 2, NH, NCH 3, -OCO-, -NHCONH-, -NHCO-, - NRSO 2 A-, -COO-, -CONH-, -NCH 3 CO-, -CONCH 3 - and/or by -CH=CH- groups and/or, in addition, 1-11 H atoms may be replaced by F and/or Cl and which is unsubstituted or mono-, di- or trisubstituted by =S, =NR, =O, OH, NH 2, SO 2 CH 3, SO 2 NH 2, CN, CONH 2, NHCOCH 3 and/or NHCONH 2, Hal is F, Cl, Br or I, and physiologically acceptable salts, solvates and stereoisomers thereof, including mixtures thereof in all ratios. I 1, I 2, I 3, I 4, I 5, independently of one another, are N or CR', T is a phenyl, biphenyl or naphthyl which is unsubstituted or mono-, di, tri- or tetrasubstituted by R, or a mono- or bicyclic saturated, unsaturated or aromatic heterocycle having 1 to 4 N, O and/or S atoms, which may be mono-, di- or trisubstituted by R, =S, =NR' and/or =O, R 1 is isopropyl, 2-butyl or isobutyl, R 2 is n-propyl, isopropyl, 2-butyl or isobutyl, A 1 is leucine or a single bond, A 2 is valine, n is 0, Y is OH or O-benzyl, m is 1, L 1 is -(C=O)-, X is a linear or branched alkyl having 1-10 C atoms or cyclic alkyl having 3-10 C atoms, in which one, two or three CH 2 groups may be replaced, independently of one another, by O and which is unsubstituted or mono- or disubstituted by T, L 2 is a single bond, R,R', independently of one another, are H, linear or branched alkyl having 1-10 C atoms, in which one, two or three CH 2 groups may be replaced, independently of one another, by O, S, SO, SO 2, NH, NCH 3, -OCO-, -NHCONH-, -NHCO-, - NRSO 2 A-, -COO-, -CONH-, -NCH 3 CO-, -CONCH 3 -, -C≡C- groups and/or by -CH=CH- groups and/or, in addition, 1-20 H atoms may be replaced by F and/or C and which is unsubstituted or mono-, di- or trisubstituted by =S, =NR, =O, Hal, OH, NH 2, SO 2 CH 3, SO 2 NH 2, CN, CONH 2, NHCOCH 3 and/or NHCONH 2, or cyclic alkyl having 3-7 C atoms, in which one, two or three CH 2 groups may be replaced, independently of one another, by O, S, SO, SO 2, NH, NCH 3, -OCO-, -NHCONH-, -NHCO-, - NRSO 2 A-, -COO-, -CONH-, -NCH 3 CO-, -CONCH 3 - and/or by -CH=CH- groups and/or, in addition, 1-11 H atoms may be replaced by F and/or Cl and which is unsubstituted or mono-, di- or trisubstituted by =S, =NR, =O, OH, NH 2, SO 2 CH 3, SO 2 NH 2, CN, CONH 2, NHCOCH 3 and/or NHCONH 2, Hal is F, Cl, Br or I,