Prenatal nicotine exposure induces cardiac adrenergic subsensitivity in adult rats

ABSTRACT

Adult offsprings of Wistar female rats treated during pregnancy (days 1-20) with nicotine (1 mg/kg s.c.,b.i.d.), were tested in order to detect possible alterations in the reactivity of the cardiovascular system to sympathetic agonists. Dose-response curves to the pressor response of noradrenaline (NA) did not show any differences between control and experimental animals. However, cumulative dose-response curves to the chronotropic effect of NA on isolated atria were significantly shifted to the right in nicotine prenatal treated rats than in controls. Accordingly, 3H-dihydroalprenolol binding was significantly reduced in hearts of experimental animals as compared with controls, without any change in affinity. These data demonstrate long lasting deleterious effects induced by prenatal nicotine exposure, probably resulting from alterations in the sympathetic system during the developing stage.