Structure and function of cerebral and mesenteric resistance arteries in low-dose endotoxin-infused pregnant rats

Marjon J Wiegman; Anne Marijn Van der Graaf; Robert H Henning; Gerda G Zeeman; Hendrik Buikema; Marijke M Faas

doi:10.1016/j.preghy.2012.11.002

Structure and function of cerebral and mesenteric resistance arteries in low-dose endotoxin-infused pregnant rats

Pregnancy Hypertens. 2013 Jan;3(1):48-56. doi: 10.1016/j.preghy.2012.11.002. Epub 2012 Dec 3.

Authors

Marjon J Wiegman¹, Anne Marijn Van der Graaf², Robert H Henning³, Gerda G Zeeman⁴, Hendrik Buikema³, Marijke M Faas⁵

Affiliations

¹ School of Behavioral and Cognitive Neurosciences, University of Groningen, University Medical Center Groningen, The Netherlands; Department of Obstetrics and Gynecology, University of Groningen, University Medical Center Groningen, The Netherlands; Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, The Netherlands. Electronic address: mj.wiegman@umcg.nl.
² Department of Obstetrics and Gynecology, University of Groningen, University Medical Center Groningen, The Netherlands; Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, The Netherlands.
³ Department of Clinical Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands.
⁴ School of Behavioral and Cognitive Neurosciences, University of Groningen, University Medical Center Groningen, The Netherlands; Department of Obstetrics and Gynecology, University of Groningen, University Medical Center Groningen, The Netherlands.
⁵ Division of Medical Biology, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, The Netherlands.

PMID: 26105741
DOI: 10.1016/j.preghy.2012.11.002

Abstract

Objective: Since the cerebrovasculature likely plays a prominent role in the pathophysiology of eclampsia, we assessed the effects of low-dose endotoxin-induced experimental preeclampsia on the function and structure of rat posterior cerebral arteries (PCA) and mesenteric arteries (MA).

Methods: Nonpregnant (NP) and pregnant (P) rats were infused with saline (NP-CTL, n=9; P-CTL, n=9) or low-dose endotoxin (NP-endotoxin, n=9; P-endotoxin, n=10). Myogenic activity, pressure of forced dilatation (FD) and structural properties were evaluated in PCA and MA.

Results: PCA underwent FD between 125 and 150mmHg in P-endotoxin (repeated measures ANOVA vs 75mmHg; P<0.05) and between 150 and 175mmHg in P-CTL and NP animals (repeated measures ANOVA vs 75mmHg; P<0.05). PCA myogenic tone was unaffected by pregnancy or endotoxin, however, pregnancy decreased the MA myogenic tone (P<0.05 vs NP). Passive characteristics of PCA and MA were unaffected by pregnancy or endotoxin.

Conclusion: Low-dose endotoxin-infusion during pregnancy, but not pregnancy alone, decreased the pressure of FD in PCA. This may predispose to cerebral autoregulatory breakthrough and edema formation during increased blood pressure as seen in eclampsia.

Keywords: Cerebral arteries; Low-dose endotoxin; Mesenteric arteries; Myogenic tone; Pregnancy.