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

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.

Oxidative Stress in Maternal Blood and Placenta From Mild Diabetic Rats

“…[12][13][14][15] In contrast, there are no studies evaluating mild diabetes-induced placental effects. Therefore, the aim of this study was at evaluating the effects of oxidative stress status in maternal blood and in the placentas of mild diabetic rats and investigating superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rd) activities, and malondialdehyde (MDA) levels at term pregnancy.…”

Impact of Maternal Over-nutrition during Pregnancy on Maternal Oxidative Stress and Fetal Skeletal/Visceral Anomalies of the Rats

“…The morning on which sperm were found in the vaginal smear was designated Gestational Day 0 [6]. The female rats were randomly distributed into two groups (n = 21 rats/group): Control group -fed regular diet; Overnutrition group -fed high caloric diet from day 0 to day 21 …”

“…GSH-Px activity was expressed in enzymatic activity units per gram of hemoglobin (IU/gHb). For MDA concentration, the absorbance was measured at a wavelength of 535 nm, and the results were expressed as nM of MDA per gram of hemoglobin (nM/g Hb) according protocol of our laboratory [6].…”

Physiological and biochemical measurements before, during and after pregnancy of healthy rats

“…In relation the physiological and biochemical changes in the different periods analyzed, it was observed that the rats gained body weight during pregnancy related to fetal and extraembryonic membranes development, according to others studies of our laboratory [18][19][20][21][22] . The blood glucose level in pregnancy and lactation periods was reduced, showing nutrient exchange from mother to offspring as energy source.…”

“…Then, the increased fetal weight consequently led to maternal weight gain on day 20 pregnancy [18][19][20][21][22] . The progressive increase in triglyceride levels during pregnancy may be related to preparation for lactogenesis and also for the milk production or feeding of offspring.…”