Evidence for the involvement of vasopressin in the pathophysiology of adriamycin-induced nephropathy in rats.

The effect of orally available, nonpeptide vasopressin V1 and V2 receptor antagonists on chronic progressive glomerular disease was investigated in Wistar rats with Adriamycin-induced nephropathy. At weeks 0 and 3, Adriamycin was injected twice, and at week 3 drugs started to be given as follows: groups 2 and 3 were treated with V1 and V2 antagonists, respectively, while the untreated group 1 served as control. To block the effects of vasopressin totally, both V1 and V2 antagonists were simultaneously administered (group 4). At weeks 8 and 10, V1 and V2 antagonists given either alone or combined significantly reduced the urinary protein excretion to the same levels. Urinary volume increased in groups 3 and 4 from week 4. Systolic blood pressure did not significantly increase in all groups during the study. Histological alterations in the kidney of groups 2, 3 and 4 were significantly attenuated compared to the control. These results suggest that both vasopressin V1 and V2 agonism plays a role in the pathophysiology of Adriamycin-induced nephropathy despite plasma levels of vasopressin within the normal range. These findings also lead to the notion that in some types of nephrotic patients these orally available V1 and/or V2 receptor antagonists may be effective for reduction of proteinuria and for retardation of progression of renal failure.