J.'.~"";i'

Review ofLiterature
gestation while there was no difference reported in urinary excretion rates
ofcalcium between normotensive and hypertensive pregnant women.
Millar et al., (1996), suggested that measurement of inactive
urinary kallikrein, creatinine in a random urine sample collected between
16-20 weeks gestation could be used for early prediction of pre­
eclampsia.
Urinary kallikrein excretion has been shown to increase in
normotensive pregnancy , whereas in preeclampsia reduced levels as
compared to non-pregnant subjects have been found (Baker, 1993).
3- Urinary Excretion of Prostacyclin Metabolites:
Evidence is accumulating that a relative deficiency of vascular
prostacyclin plays an important role in the development ofpreeclampsia.
(Fitzgerald et al., 1987) reported that a reduction in the urinary excretion
of 2,3-dinor-6 keto- prostaglandin FI, a major metabolite ofprostacyclin,
precede the development of clinical diseas.
4 - Platelet angiotensin II receptors:
(Dekker and Sibai 1991), showed that a physiologic fall in platelet
angiotensin II binding occur in early pregnancy, which is parallel to that
ofthe vascular response to angitensin II.
lt was found that platelet angiotensin II receptors are increased in
pre-elcampsia, problably as an expression of the altered angiotensin II
levels; this increase was shown to precede the increase in blood pressure.
S - Platelet calcium response to arginine vasopressin:
An increase in the sensitivity of platelet calcium to argmme
vasopressin was proposed to be useful as an early predictor of subsequent
pre-eclampsia, it was shown that the sensitivity ofplatelet intracellular
calcium levels to arginine vasopressin in pateint with subsequent pre­
eclampsia is already increased at the end of first trimester, as compared
with normotensive pregnancy (Zemel et al, 1990) .
43