INTRODUCTION: Diabetes is a well-known risk factor in pregnancy. Because maternal diabetes involves oxidative stress that is also induced by chronic hypoxia and can alter vascular function, we sought to determine the effects of chronic maternal hyperglycemia on the fetoplacental vasculature in rats and to compare it with the effects of chronic hypoxia. METHODS: Diabetes was induced in female rats by a streptozotocin injection at a neonatal age. When these animals reached adulthood, their hyperglycemia was confirmed and they were inseminated. Half of them were exposed to hypoxia (10% O2) for the last week before the delivery. One day before the expected date of delivery, one of their placentae was isolated and perfused. RESULTS: Fetoplacental vascular resistance was increased equally by experimental diabetes, chronic hypoxia, and their combination. Fetoplacental perfusion pressure-flow analysis suggested increased resistance in the small vessels in chronic hypoxia and in larger vessels in diabetes. Fetal plasma nitrotyrosine levels, measured as a marker of peroxynitrite (reaction product of superoxide and nitric oxide), mirrored the differences in fetoplacental resistance, suggesting a causative role. Fetoplacental vasoconstrictor reactivity to acute hypoxic stimuli was reduced similarly in all groups. Fasudil, a strong vasodilator agent, reduced fetoplacental vascular resistance similarly in all groups, suggesting that for the observed differences among the groups, the changes in vascular morphology were more important than variances in vascular tone. DISCUSSION: Maternal diabetes increases fetoplacental vascular resistance to a similar extent as chronic hypoxia. These stimuli are not additive. Changes in vascular tone are not responsible for these effects.
- MeSH
- cévní rezistence fyziologie MeSH
- experimentální diabetes mellitus metabolismus patofyziologie MeSH
- gestační diabetes metabolismus patofyziologie MeSH
- hypoxie metabolismus patofyziologie MeSH
- krysa rodu rattus MeSH
- oxidační stres fyziologie MeSH
- placenta krevní zásobení MeSH
- placentární oběh fyziologie MeSH
- těhotenství MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
- MeSH
- AMPA receptory antagonisté a inhibitory MeSH
- chování při pití účinky léků MeSH
- excitační aminokyseliny antagonisté a inhibitory farmakologie MeSH
- krysa rodu rattus MeSH
- mikroinjekce MeSH
- nucleus basalis Meynerti cytologie fyziologie MeSH
- valeráty farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- MeSH
- krysa rodu rattus MeSH
- způsoby aplikace léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
