Cigarette smoke pollution promotes oxidative stress imbalance and hormonal changes affecting pregnancy outcome in rats

Abstract

Background: The deleterious effect of cigarette smoke on several health parameters due to pollution of air is of international concern. How these affect all living organisms and their wellbeing is a major research area. The development of oxidative stress, alteration in lipid peroxidation, thyroid and pregnancy hormone pattern was examined in pregnant rats exposed to cigarette smoke throughout the gestation period.
Methods: Cigarette smoke exposed and control pregnant rats were sacrificed at gestational day 6, 12 and 20. Serum was collected for hormonal assay. Some vital organs were also dissected out, homogenized and used for oxidative stress and lipid peroxidation assay. Gestational weights, corporal luteum and implanted embryos were also recorded.
Results: There was a significant increased loss of corpora lutea, embryonic implants and a disruption of the hormonal pattern of LH, progesterone and estradiol during pregnancy in cigarette smoke exposed rats. A significant increase in serum cortisol and brain tissue level of MDA, SOD and a significant decrease in GSH in cigarette smoke exposed rats was recorded.
Conclusion: Exposing pregnant rats to cigarette smoke precipitated oxidative stress, early loss of corpora lutea, disruption in hormonal pattern and an increasing loss of embryonic implants.

Keywords: Cigarette smoke, implantation, corpus luteum, pregnancy, female sex hormone, thyroid hormone, oxidative stress