The aim of this study was to evaluate the effects of maternal nicotine exposure on heart morphology and fibrosis in rat offspring. Nicotine was administered to pregnant Sprague-Dawley rats by using a subcutaneous osmotic mini-pump at a dose of 6 mg/kg/day from Gestational Days 7-21 or Gestational Day 7 to Postnatal Day 14. A control group received an equal volume of saline by the same route as nicotine. Rats born to prenatal nicotine-treated dams exhibited significantly greater cell width of cardiomyocytes, fewer cardiomyocyte nuclei number, higher β-myosin heavy chain and transforming growth factor (TGF-β1) expression, and higher collagen deposition in heart compared with rats born to normal saline-treated dams on Postnatal Days 7 and 21. Postnatal nicotine exposure further enhances these effects. We conclude that TGF-β1 may be involved in the pathogenesis of cardiac remodeling induced by maternal nicotine exposure during gestation and lactation in rat offspring.
Keywords: Collagen; Myosin heavy chain; Nicotine; Transforming growth factor-β1.
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