Glomerular and proximal tubule cysts as early manifestations of

Background. The homozygous deletion of Pkd1 in the mouse results in embryonic lethality with renal cysts and hydrops fetalis, but there is no precise data on the segmental origin of cysts and potential changes associat-ed with polyhydramnios. Methods.We used Pkd1-null mice to investigate cystogen-esis and analyze the amniotic fluid composition from em-bryonic day 12.5 (E12.5) to birth (n = 257 embryos). Results. Polyhydramnios was consistently observed from E13.5 in Pkd1−/ − embryos, in absence of placental abnor-malities but with a significantly higher excretion of sodi-um and glucose from E13.5 through E16.5, and increased cyclic adenosine 3'5-monophosphate (cAMP) levels at E14.5 and E15.5. The Pkd1−/ − embryos started to die a