Effects of exposure to cigarette smoke prior to pregnancy in diabetic rats.

Débora C Damasceno,Bruna Dallaqua,Maricelma S De Souza,Kleber E Campos,Marilza V Rudge,Paula H Lima,Yuri K Sinzato,Gustavo T Volpato,Iracema M Calderon

doi:10.1186/1758-5996-3-20

Abstract

BackgroundThe purpose of this study was to evaluate the effects of cigarette smoke exposure before pregnancy on diabetic rats and their offspring development.MethodsDiabetes was induced by streptozotocin and cigarette smoke exposure was conducted by mainstream smoke generated by a mechanical smoking device and delivered into a chamber. Diabetic female Wistar rats were randomly distributed in four experimental groups (n minimum = 13/group): nondiabetic (ND) and diabetic rats exposed to filtered air (D), diabetic rats exposed to cigarette smoke prior to and into the pregnancy period (DS) and diabetic rats exposed to cigarette smoke prior to pregnancy period (DSPP). At day 21 of pregnancy, rats were killed for maternal biochemical determination and reproductive outcomes.ResultsThe association of diabetes and cigarette smoke in DSPP group caused altered glycemia at term, reduced number of implantation and live fetuses, decreased litter and maternal weight, increased pre and postimplantation loss rates, reduced triglyceride and VLDL-c concentrations, increased levels of thiol groups and MDA. Besides, these dams presented increased SOD and GSH-Px activities. However, the increased antioxidant status was not sufficient to prevent the lipid peroxidation observed in these animals.ConclusionDespite the benefits stemming from smoking interruption during the pregnancy of diabetic rats, such improvement was insufficient to avoid metabolic alterations and provide an adequate intrauterine environment for embryofetal development. Therefore, these results suggest that it is necessary to cease smoking extensive time before planning pregnancy, since stopping smoking only when pregnancy is detected may not contribute effectively to fully adequate embryofetal development.

Highlights

The purpose of this study was to evaluate the effects of cigarette smoke exposure before pregnancy on diabetic rats and their offspring development
Rats were randomly distributed into four groups (n minimum = 15/group): nondiabetic (ND) and diabetic rats exposed to filtered air (D), diabetic rats exposed to cigarette smoke prior to and into the pregnancy period (DS) and diabetic rats exposed to cigarette smoke prior to pregnancy period (DSPP)
The rats exposed to cigarette smoke prior to and into the pregnancy period (DS) presented increased levels of glycemia only at day 21 of pregnancy as compared to D group (Figure 3) (p < 0.05)

Summary

Introduction

The purpose of this study was to evaluate the effects of cigarette smoke exposure before pregnancy on diabetic rats and their offspring development. Diabetes mellitus (DM) is a group of diseases characterized by high blood glucose levels that result from defects in the body’s ability to produce and/or use insulin [1]. In pregnancies complicated by diabetes, hyperglycemia and lipid metabolism alterations are associated with both maternal and fetal complications [2,3], causing reproductive abnormalities that enhance spontaneous abortion, congenital anomalies, and neonatal morbidity and mortality [4,5]. The toxic effect of maternal exposure to tobacco smoke on the fetal metabolic status is indicated by the significant disturbance of the antioxidant status in newborns exposed in utero to tobacco smoke [11]. A significant negative correlation has been observed between the number of cigarettes smoked per day by pregnant women and newborns’ weight, body mass index, length and head circumference [12]

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