AVP and Central diabetes insipidus: As the main focus of this paper is an exploration of the pharmacological activity at certain receptors of a lipidized peptide (METx), desmopressin, an approved V2 receptor agonist indicated for the treatment of diabetes insipidus and nocturnal enuresis9, was not employed in this assay as it is known that the functional activities (fluid secretion) of AVP and desmopressin in the MDCK cell line are comparable with EC50 values of 0.36 and 0.7 nM respectively36.