Hypertension and proteinuria may relate to the anti-angiotensin-11 receptor-1 agonist antibodies (AT1-AA) found in women with preeclampsia.40 Their exact role has not yet been fully elucidated41 but it is difficult to impune a direct hypertensive effect given the known decrease (rather than increase) in endogenous human angiotensin II and aldosterone activity.42 These autoantibodies may be another marker of widespread endothelial dysfunction and result from placental

ischaemia.43 While in experimental animals sFLT-1 can be induced by Small molecule library high throughput AT1-AA,44 the induction of both is possible from reduced uterine perfusion pressure and low dose cytokines infusion (tumour necrosis factor-α). It remains to be seen how these compounds indicate a causal sequence in human preeclampsia. However, an agonistic AII effect may partly explain the increases in angiotensin-11 sensitivity and even the decrease in K(f) seen in preeclampsia. This is yet to be determined. Preeclamptic nephropathy is widely considered to be a predominantly glomerular endothelial cell disorder.11 The term Selleckchem Sirolimus endotheliosis was first termed in 1959

by Spargo et al. who took advantage of the then, new technology of ultra thin sections and electron microscopy to identify the specific nature of these changes.45 They, and others have gone on to demonstrate that at the light microscopic level the glomeruli may appear normal at one extreme, to swollen and ischaemic with apparently thickened capillary walls PTK6 and reduction in capillary lumina at the other.46 The electron microscopic examination of the glomeruli typically reveals ‘endotheliosis’. Endotheliosis refers to the endothelial cell swelling resultant from the cytoplasmic expansion due to cytoplasmic vacuolation, droplet formation, cytoplasmic strands and membrane condensation.45

There is loss of the endothelial fenestrae as well as widening of the subendothelial space with deposition of hyaline material. Concordantly, the swollen endothelial cell encroaches on the capillary lumen and obliteration may occur.47 Given these changes, as well as the reduction in plasma volume and vasoconstriction, the oliguria associated with preeclampsia is not surprising12 Paramesangial deposition of fibrinoid material and mesangial expansion has also been noted.48 Although these renal histological changes have been considered pathognomonic for preeclampsia, this may not be the case. Several groups have performed antenatal renal biopsies in normal pregnant women and women with gestational hypertension.49–51 Strevenset al. demonstrated that five of 12 normal pregnant women had, albeit very mild, evidence of glomerular endotheliosis. These lesions resolve at variable rates post partum.