Treatment with an SSRI antidepressant restores hippocampo-hypothalamic corticosteroid feedback and reverses insulin resistance in low-birth-weight rats

Am J Physiol Endocrinol Metab. 2010 May;298(5):E920-9. doi: 10.1152/ajpendo.00606.2009. Epub 2010 Jan 26.

Abstract

Low birth weight (LBW) is associated with type 2 diabetes and depression, which may be related to prenatal stress and insulin resistance as a result of chronic hypothalamic-pituitary-adrenal (HPA) axis hyperactivity. We examined whether treatment with a selective serotonin reuptake inhibitor [escitalopram (ESC)] could downregulate HPA axis activity and restore insulin sensitivity in LBW rats. After 4-5 wk of treatment, ESC-exposed LBW (SSRI-LBW) and saline-treated control and LBW rats (Cx and LBW) underwent an oral glucose tolerance test or a hyperinsulinemic euglycemic clamp to assess whole body insulin sensitivity. Hepatic phosphoenolpyruvate carboxykinase (PEPCK) mRNA expression and red skeletal muscle PKB Ser(473) phosphorylation were used to assess tissue-specific insulin sensitivity. mRNA expression of the hypothalamic mineralocorticoid receptor was fivefold upregulated in LBW (P < 0.05 vs. Cx), accompanied by increased corticosterone release during restraint stress and total 24-h urinary excretion (P < 0.05 vs. Cx), whole body insulin resistance (P < 0.001 vs. Cx), and impaired insulin suppression of hepatic PEPCK mRNA expression (P < 0.05 vs. Cx). Additionally, there was a tendency for reduced red muscle PKB Ser(473) phosphorylation. The ESC treatment normalized corticosterone secretion (P < 0.05 vs. LBW), whole body insulin sensitivity (P < 0.01) as well as postprandial suppression of hepatic mRNA PEPCK expression (P < 0.05), and red muscle PKB Ser(473) phosphorylation (P < 0.01 vs. LBW). We conclude that these data suggest that the insulin resistance and chronic HPA axis hyperactivity in LBW rats can be reversed by treatment with an ESC, which downregulates HPA axis activity, lowers glucocorticoid exposure, and restores insulin sensitivity in LBW rats.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenocorticotropic Hormone / blood
  • Analysis of Variance
  • Animals
  • Area Under Curve
  • Blood Glucose / metabolism
  • Body Weight / drug effects*
  • Citalopram / pharmacology*
  • Corticosterone / blood
  • Dexamethasone / pharmacology*
  • Eating / drug effects
  • Enzyme-Linked Immunosorbent Assay
  • Feedback, Physiological / drug effects*
  • Female
  • Glucocorticoids / pharmacology
  • Glucose Clamp Technique
  • Glucose Tolerance Test
  • Glucose Transporter Type 4 / metabolism
  • Hippocampus / drug effects*
  • Hippocampus / metabolism
  • Hypothalamo-Hypophyseal System / drug effects
  • Hypothalamo-Hypophyseal System / metabolism
  • Hypothalamus / drug effects*
  • Hypothalamus / metabolism
  • Insulin / blood
  • Insulin Resistance / physiology*
  • Male
  • Muscle, Skeletal / metabolism
  • Neural Pathways / drug effects
  • Neural Pathways / metabolism
  • Phosphorylation / drug effects
  • Pituitary-Adrenal System / drug effects
  • Pituitary-Adrenal System / metabolism
  • Pregnancy
  • Prenatal Exposure Delayed Effects / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Glucocorticoid / metabolism
  • Receptors, Mineralocorticoid / metabolism
  • Restraint, Physical
  • Reverse Transcriptase Polymerase Chain Reaction
  • Selective Serotonin Reuptake Inhibitors / pharmacology
  • Stress, Physiological / drug effects

Substances

  • Blood Glucose
  • Glucocorticoids
  • Glucose Transporter Type 4
  • Insulin
  • RNA, Messenger
  • Receptors, Glucocorticoid
  • Receptors, Mineralocorticoid
  • Serotonin Uptake Inhibitors
  • Citalopram
  • Dexamethasone
  • Adrenocorticotropic Hormone
  • Proto-Oncogene Proteins c-akt
  • Corticosterone