IMPORTANCE OF ANTIDIURETIC PROPERTIES OF VASOPRESSIN IN EXPERIMENTAL RENAL HYPERTENSION

1. Homozygous Brattleboro rats with hereditary hypothalamic diabetes insipidus (DI) developed one-kidney, one-clip (1K–1C) and two-kidney, one-clip (2K–1C) Goldblatt renal hypertension. 2. However, the systolic blood pressure (SBP) in 1K–1C Brattleboro rats was significantly lower than in non-DI hypertensive 1K–1C Long-Evans (LE) rats. 3. Treatment with the synthetic antidiuretic analogue of vasopressin, DDAVP (l-desamino-8-D-arginine vasopressin), increased the SBP in the DI rats to the same level as in 1K–1C Long-Evans. This elevation of SBP was associated with increased extracellular fluid volume in the DI rats after DDAVP. 4. The results suggest that vasopressin is not essential for the development of renal hypertension but the absolute levels of blood pressure achieved in 1K–1C hypertension are volume-dependent and thus influenced by the water-retaining properties of vasopressin.