Insulin resistance and impaired baroreflex gain during pregnancy

Daisy L. Daubert, Mee Young Chung, Virginia Brooks

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Pregnancy decreases baroreflex gain, but the underlying mechanism is unclear. Insulin resistance, which has been associated with reduced transport of insulin into the brain, is a consistent feature of many conditions exhibiting impaired baroreflex gain, including pregnancy. Therefore, using conscious pregnant and nonpregnant rabbits, we tested the novel hypothesis that the pregnancy-induced impairment in baroreflex gain is due to insulin resistance and reduced brain insulin. Baroreflex gain was determined by quantifying changes in heart rate in response to stepwise steady-state changes in arterial pressure, secondary to infusion of nitroprusside and phenylephrine. We found that insulin sensitivity and baroreflex gain were strongly correlated in nonpregnant and term pregnant rabbits (r2 = 0.59). The decrease in insulin sensitivity and in baroreflex gain exhibited similar time courses throughout pregnancy, reaching significantly lower levels at 3 wk of gestation and remaining reduced at 4 wk (term is 31 days). Treatment of rabbits with the insulin-sensitizing drug rosiglitazone during pregnancy almost completely normalized baroreflex gain. Finally, pregnancy significantly lowered cerebrospinal fluid insulin concentrations. These data identify insulin resistance as a mechanism underlying pregnancy-induced baroreflex impairment and suggest, for the first time in any condition, that decreased brain insulin concentrations may be the link between reductions in peripheral insulin sensitivity and baroreflex gain.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume292
Issue number6
DOIs
StatePublished - Jun 2007

Fingerprint

Baroreflex
Insulin Resistance
Pregnancy
Insulin
rosiglitazone
Rabbits
Brain
Nitroprusside
Phenylephrine
Cerebrospinal Fluid
Arterial Pressure
Heart Rate

Keywords

  • Cerebrospinal fluid
  • Conscious rabbits
  • Insulin sensitivity
  • Rosiglitazone

ASJC Scopus subject areas

  • Physiology

Cite this

Insulin resistance and impaired baroreflex gain during pregnancy. / Daubert, Daisy L.; Chung, Mee Young; Brooks, Virginia.

In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, Vol. 292, No. 6, 06.2007.

Research output: Contribution to journalArticle

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