Reduction of the Human Placental Vascular Relaxation to Progesterone by Gestational Diabetes.

Publication/Presentation Date

3-1-1998

Abstract

>Background: We have recently described a dose-dependent, endothelium-independent relaxation to progesterone in human placental arteries and veins. This receptor-operated, cAMP-mediated relaxation may be of value in maintaining adequate blood flow in the placental circulation.Objective: To investigate if gestational diabetes alters this relaxation to progesterone.Study design: Isolated human placental vessels from pregnancies complicated by gestational diabetes and well matched controls (uncomplicated term pregnancies), incubated in Krebs-bicarbonate buffer and submaximally precontracted with KCl, were exposed to cumulative doses of progesterone (0.01-30 µmol/liter), nitroglycerin (0.001-1 µmol/liter), arachidonic acid (0.01-10 µmol/liter), forskolin (0.01-10 µmol/liter) and 5-hydroxytryptamine (serotonin, 0.01-10 µmol/liter).Results: The relaxation to progesterone in vessels from patients with gestational diabetes was reduced by 50-100% in both arteries and veins compared with control (for example, relaxation to 10 µmol/liter progesterone was reduced from 52 +/- 7 to 18.8 +/- 5.4% in arteries and from 58 +/- 8 to 19 +/- 5.2% in veins, n = 7-13, P < 0.05), whereas responses to the other vasoactive agents were unchanged.Conclusion: Based on these results, gestational diabetes significantly reduces the relaxation to progesterone in human placental vessels. This alteration of the relaxation to progesterone may lead to an increase in placental vascular resistance and possibly to a reduction of placental blood flow.

Volume

8

Issue

1

First Page

27

Last Page

30

ISSN

0939-6322

Disciplines

Medicine and Health Sciences | Pediatrics

PubMedID

9524156

Department(s)

Department of Pediatrics

Document Type

Article

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