Prostacyclin production by human umbilical vein endothelium in response to serum from patients with systemic sclerosis

Raynaud’s Phenomenon and Vascular Disease in Systemic Sclerosis

Raynaud's phenomenon (RP) is very often the first manifestation of SSc preceding the onset of all the other signs and symptoms of the disease. Two structures are involved in the pathogenesis of RP: the endothelium and the peripheral nervous system (PNS). The hypothesis is that SSc modifies consistently the activity of both these systems leading eventually to RP. The disease, through the injury to the endothelium, jeopardizes the basilar endothelial-dependent vascular tone control. An increase of endothelin, a potent endothelial-derived vasoconstrictor, and the reduction of nitric oxide, one of the main endothelial vasodilators, are two key events involved in the genesis of RP. The PNS is also targeted by the disease as demonstrated by the high incidence of neuropathy in SSc patients. A marked reduction of sensory fibres has been detected in SSc skin. Thus, the involvement of nerve terminals reduces the vasodilatory, endothelial dependent or independent, potential of the neuropeptides released by sensory nerve endings. Indeed, an increased sensitivity of alpha 2 adrenoceptors mediated vasoconstriction has been shown in SSc skin. The complex vasodilatory network formed by the interaction between the endothelium and the PNS seems greatly damaged by SSc leading inesorably toward vascular tone dysfunction clinically evident as RP.

Preeclampsia: the effects of serum on endothelial cell prostacyclin, endothelin, and cell membrane integrity

OBJECTIVE

Our purpose was to determine whether serum from women with preeclampsia or gestational hypertension (1) decreased endothelial cell prostacyclin, (2) increased endothelial cell endothelin, and (3) caused endothelial cell damage.

STUDY DESIGN

Production of 6-keto-prostaglandin F1 alpha and endothelin by cultured endothelial cells was measured after 48 hours' incubation with sera from 23 nonpregnant women, 23 normal pregnant women, 12 women with preeclampsia, and 11 women with gestational hypertension. Structure damage of endothelial cells was assessed by a chromium release assay.

RESULTS

Serum from normal pregnant women induced more endothelial prostacyclin but less endothelin than did serum form nonpregnant women (p<0.05). No difference was found between normal pregnant and hypertensive pregnant women for prostacyclin production, but serum of preeclamptic women induced less endothelin production than did that of normal pregnant women (p<0.05). Chromium 51 release by endothelial cells was similar between normal pregnant and hypertensive pregnant groups.

CONCLUSIONS

Serum from preeclamptic women stimulates less endothelin production than does serum from normal pregnant women but does not alter prostacyclin production and is not cytotoxic to endothelial cells after short-term incubation.