The mechanism by which angiotensin-converting enzyme inhibitors reduce red cell mass in renal transplant recipients with @entity6582 is unclear. To examine the role of @entity2178 in this disorder, @entity9886 (a competitive antagonist of the @entity2178 type 1 [ @entity7743 ] receptor) was administered to 23 @entity1 with @entity6582 . Fourteen @entity1 took 25 mg/d for 8 wk; nine others were treated with 50 mg/d for 8 wk. Hematocrit decreased from 0.527 +/- 0.027 to 0.487 +/- 0.045 after 8 wk (P < 0.01)--by at least 0.04 in 19 @entity1 . Decrement in hematocrit in the initial 8 wk of therapy was significantly greater in @entity1 administered 50 mg/d than in @entity1 on 25 mg/d. Twelve of 14 @entity1 initially treated with 25 mg/d showed a small change in hematocrit; the dose was increased to 50 mg/d for 8 more wk. Hematocrit decreased from 0.528 +/- 0.030 before @entity9886 treatment to 0.483 +/- 0.055 after 16 wk (P < 0.01). After therapy, serum @entity1307 significantly decreased in eight @entity1 with elevated baseline levels, but not in 15 @entity1 with normal baseline levels; however, hematocrit significantly decreased in both groups. @entity9886 was withdrawn in 16 @entity1 ; hematocrit increased from 0.440 +/- 0.057 to 0.495 +/- 0.049 after 8.9 +/- 7.5 wk (P < 0.001), without change in serum @entity1307 . Thus, specific blockade of @entity7743 receptors inhibited erythropoiesis, suggesting a pathogenic role for @entity2178 in posttransplant @entity6582 .

XXXX , an @entity7743 antagonist, lowers hematocrit in posttransplant @entity6582 .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity6582 :: ('MESH:D011086', 'Disease') :: ['erythrocytosis'] @entity2178 :: ('183', 'Gene') :: ['angiotensin II'] @entity1307 :: ('2056', 'Gene') :: ['erythropoietin'] @entity9886 :: ('MESH:D019808', 'Chemical') :: ['losartan', 'Losartan'] @entity7743 :: ('185', 'Gene') :: ['AT1']
@entity9886 :: (MESH:D019808,Chemical) :: ['Losartan']
