Full biological characterization of two linear vasopressin analogues - [Phaa,D-Tyr(Et).sup.2./sup.,Aib.sup.4./sup.,Arg.sup.6./sup.,Tyr(NH.sub.2./sub.).sup.9./sup.]AVP and [Phaa,D-Tyr(Et).sup.2./sup.,Arg.sup.6./sup.,Aib.sup.7./sup.,Tyr(NH.sub.2./sub.).sup.9./sup.]AVP