Figure 1032

Hypertension in preeclampsia. Although the mechanism of the increased blood pressure in preeclampsia is not established, evidence suggests it may involve multiple processes. A possible scenario involves the following: decreased placental production of estrogen and progesterone, both of which have hemodynamic effects; increased circulating endothelial toxins, possibly released from a poorly perfused placenta; and increased activity of the sympathetic nervous system. These processes may then result in alterations in platelet- vascular endothelial cell function, with decrease in vasodilators such as nitric oxide and prostacyclin and increased production of vasoconstrictors such as endothelin (ET). Compensatory suppression of the renin-angiotensin system occurs, suggesting that excess angiotensin II (AII) does not play a major role in preeclamptic hypertension (HT). Finally, sodium retention owing to renal vasoconstriction may further increase blood pressure. cAMP—cyclic adenosine monophosphate; cGMP— cyclic guanosine monophosphate; 5-HT— serotonin; PThr— parathyroid hormone; S2—serotonergic receptors; Thr—thombin TX— thromboxane; TXA2— thromboxane A2. (Adapted from Luscher and Dubey [28]; with permission.)

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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