Conopressins and their analogs: synthesis, antidiuretic and behavioral effects

[Lys8]-Conopressin G (L1), and [Arg8]-Conopressin S (A1) and their four analogs were synthesized using solid phase procedure. These analogs are [2-thiopropionic acid1, lys8]-conopressin (L2), [2-thiopropionic acid1, Arg8]-conopressin (A2), [cis-4-methyl-1-thiocyclohexaneacetic acid1, Lys8], conopressin (L3), and [cis-4-methyl-1-thiocyclohexaneacetic acid1, ARg8]-conopressin (A3). Behavioral and diuretic effects of all six peptides were compared with these of [Arg8]-vasopressin (AVP). Conopressin A1, and L1 and their analogs A2, A3, L2, L3, induced antidiuretic effects. After icv injection of some conopressins, barrel rotatory behavior of rats was observed.