Endothelin-1 inhibits AVP-stimulated osmotic water permeability in rat inner medullary collecting duct.

摘要: Endothelin causes diuresis despite an accompanying decrease in glomerular filtration rate and renal plasma flow. Binding sites for endothelin are located not only glomeruli but also the inner medulla, possibly medullary collecting ducts (IMCD). To determine whether has a direct tubular effect, effects of on water urea transport were investigated using isolated microperfusion rat IMCD segments vitro. Endothelin, at 10(-10) 10(-8) M, reversibly inhibited 10(-11) M arginine vasopressin (AVP)-stimulated osmotic permeability (Pf) by 18 24%, respectively. (10(-8) M) Pf 23% presence much higher dose AVP (10(-9) M), whereas had no effect absence AVP. On other hand, did inhibit stimulated 10(-3) dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP). inhibitory AVP-stimulated permeability. These data suggest that endo...