Endothelial-derived relaxing factor released by endothelial cells of human umbilical vessels and its impairment in pregnancy-induced hypertension.

The principal objective of this study was to determine and compare the capability of human umbilical vessels of normal and pregnancy-induced hypertensive parturients to produce and to release the endothelial-derived relaxing factor. A bolus of bradykinin injected in the perfusion system of human umbilical vessels induces a release of a relaxant factor, detectable by bioassay, that is pharmacologically similar to the endothelial-derived relaxing factor. Human umbilical cords were collected from normal and pregnancy-induced hypertensive parturients. In the latter group the release of endothelial-derived relaxing factor is extremely reduced. In fact, in umbilical vessels collected from normal parturients, bradykinin at a dose of 20 pmol produces a release of endothelial-derived relaxing factor equivalent to a relaxation induced by 59.9 +/- 11.0 and 30.8 +/- 11.4 pmol of glyceryl trinitrate for the artery and vein, respectively. The same dose of bradykinin in umbilical vessels, collected from pregnancy-induced hypertensive parturients, produces a release equivalent to 6.6 +/- 2.2 and 5.7 +/- 3.5 pmol of glyceryl trinitrate equivalent for the artery and vein, respectively. Neither an increasing bolus of exogenous bradykinin or an infusion of superoxide dismutase or L-arginine was able to restore the production of endothelial-derived relaxing factor to normal levels. Our results indicate a probable alteration of endothelial cell numbers or an alteration of the enzymatic pathway, probably due to cytotoxic endogenous factors produced in pregnancy.

Vaginal administration of gemeprost for preoperative cervical dilatation in non pregnant patients.

The use of Gemeprost vaginal suppositories has been evaluated in a trial for induction of the cervical dilatation in non pregnant women. 30 voluntary patients, 22 nulliparous and 8 pluriparous, had to be subjected to biopsy of the endometrium; 24 were treated for the control of sterility and 6 for menstrual perimenopausal disorders. The biopsies of the sterility control were effected in the second half of the cycle, generally without having recourse to narcosis. A single Gemeprost pessary containing 1 mg of 16, 16-dimethyl-trans-delta 2 PGE1 methyl ester was intravaginal administered, deeply into the posterior fornix, 3 hours before the biopsy. The success rate was 86.66 (26 pts.) with an average dilatation of 5.38 H (Hegar) +/- 0.75 SD. For 4 patients (13.33%) having a dilatation less than 4 H, it was necessary to complete the dilatation mechanically. All the observed side effects presented a modest intensity: cephalalgia 6.6% (no. 2), gastralgia 3.3% (no. 1), vaginal burning 6.6% (no. 2). No significant variation of vital function parameters was recorded. In conclusion this type of preparation of the cervix has permitted us to achieve a more gradual dilatation and to prevent the traumata of the cervico-isthmic system due to forced mechanical dilatations by the exclusive use of Hegar's dilators.

Reduced regulatory thermogenesis in pregnant and ovariectomized women.

Diet-induced thermogenesis has been evaluated in five ovariectomized young women, five late pregnant (at the 8th month of pregnancy) and five age matched lean control women. Post-prandial thermogenesis was tested after a 900 Kcal mixed meal. Although pregnant (p less than 0.05) and ovariectomized showed a basal metabolic rate higher than control females, both groups had a significantly lower post-prandial thermogenesis when compared to the lean one (p less than 0.05). It is concluded that post-prandial thermogenesis is depressed in pregnant and ovariectomized females and that this condition may facilitate, at least in predisposed adult women, the development of obesity.