Nitric oxide synthesis is increased after dehydroepiandrosterone sulphate administration in term human pregnancy

Abstract

The purpose of this study was to evaluate the role of nitric oxide in the vasodilative effect of dehydroepiandrosterone sulphate (DHEA-S) in term pregnant women. Circulating nitrite, nitrate and oestradiol concentrations were measured on 10 normal full-term pregnant women before (-30 min) and after (10, 30, 60, 90 and 120 min) administration of a 200 mg i.v. dose of DHEA-S dissolved in 20 ml of 5% dextrose (DHEA-S group). Ten normal full-term pregnant women received 20 ml of 5% dextrose as controls (control group). Maternal blood pressure and heart rate were also recorded. The median oestradiol concentration increased significantly after the infusion in DHEA-S group (P < 0.001), whereas there was no significant change in plasma oestradiol in the control group. In the DHEA-S group, plasma circulating nitrate and nitrite increased significantly at 10 and 30 min after DHEA-S administration respectively (P < 0.05). In the control group, there was no change in plasma nitric oxide (NO) metabolites. No change was found in heart rate or mean arterial blood pressure in the control or DHEA-S groups. These results suggest there may be a link between increased NO and increased oestrogen after DHEA-S injection but their peak values did not coincide. Both may be associated with vasodilation in term pregnant women.

Evidence for the Biosynthesis of DHEA from Cholesterol by First-Trimester Human Placental Tissue: Source of Androgens

“…As a corollary to this finding, long-acting calcium channel blockers including amlodipine and nitrendipine have been observed to lower blood pressure and DHEA-S, resulting in improved hyperinsulinemia, glucose tolerance and insulin resistance [27,28]. In addition, recent studies have provided evidence that intravenous administration of DHEA and its sulfate facilitated placental blood flow in term human pregnancy by mediating a rapid increase of nitric oxide [29]. This C-19 steroid also upregulates the hyaluronic acid-induced cervical ripening process via induction of interleukin-8 and its receptors [30].…”

The Influence of Parturition on the Level and Synthesis of Sulfated and Free Neurosteroids in Rats

“…While previous studies have demonstrated a decrease in DHEAS levels over pregnancy with an increase at labor [18][19][20] as well as increased DHEAS in preterm labor [21,22], this study is the first to investigate DHEA, DHEAS, PN, PS and their associated metabolic enzyme in a comprehensive manner during the pre-and postdelivery period. It is important to note that hypothesized modes of activity at term pregnancy for DHEA and DHEAS include effects on overall control and induction of labor [23,24] including cervical ripening [25] and vasodilative effects [26,27].…”

Enhanced dehydroepiandrosterone synthesis by amnion compared to chorion: A comparative study using the reverse-isotope dilution technique

“…Amongst its postulated biological roles, DHEA can inhibit glucoase-6-phosphate dehydrogenase (Marks and Banks, 1960), reverse insulin resistance associated with glucocorticoid treatment (Coleman et al, 1982), and more importantly in immunomodulation by potentiation of lymphocyte activation (Suitters et al, 1997). In addition to being an important precursor for estrogen biosynthesis, intravenous administration of DHEA and its sulphate has been reported to facilitate placental blood¯ow in term human pregnancy by mediating a rapid increase of nitric oxide (Manabe et al, 1999). This C-19 steroid also upregulates the hyaluronic acid-induced cervical ripening process via induction of interleukin-8 and its receptors (Belayet et al, 1999).…”