Maternal Oxidative Stress, Placental Morphometry, and Fetal Growth in Diabetic Rats Exposed to Cigarette Smoke.

The diabetic syndrome affects pregnancy, contributing to placental functional and structural disruptions and impaired fetal development, with many reports indicating tobacco-associated morbidity and perinatal mortality. In our study, an experimental rat model of diabetes and cigarette smoke exposure in pregnant rats was used to determine the impact of the combination of diabetes and exposure to cigarette smoke during pregnancy on maternal oxidative stress biomarkers and placental and fetal development. Diabetes was induced by streptozotocin, and dams were exposed to cigarette smoke by mainstream smoke generated by a mechanical smoking device and delivered into a chamber. Four groups of dams were studied: nondiabetic (C, control) and diabetic (D) exposed to filtered air and nondiabetic (CS) and diabetic (DS) exposed to cigarette smoke prior to and during pregnancy. Maternal oxidative stress biomarkers, placental morphology, and fetal growth were determined close to term. The combination of diabetes and cigarette smoke resulted in elevated maternal blood glucose levels and increased number of small fetuses. Placentas from the DS group showed increased junctional zone and decreased labyrinthine area. The morphological alterations were characterized by extensive vascular congestion, thickness, and hyalinization of the vascular walls, numerous decidual cells with abundant glycogen, and macrophages with cytoplasmic inclusions of hemosiderin. Additionally, they showed increased glycogen accumulation and junctional zone structural derangement with ectopic giant cells. No alterations were observed in maternal oxidative stress status. Thus, our result suggests that diabetes makes pregnant rats more susceptible to the adverse effects of exposure to cigarette smoke on placental morphometry and fetal growth.

Absence of histological changes after the administration of a continuous intrathecal clonidine in Wistar rats.

BACKGROUND: The administration of epidural and spinal clonidine has demonstrated an antinociceptive effect in animals and humans. For that reason, its spinal administration has been proposed as an adjuvant in chronic pain management. However, there is limited information about its possible neurotoxic effect after its continuous neuraxial administration. METHOD: Twelve male Wistar rats were randomly divided into two groups. Using an osmotic mini-pump a continuous infusion of intrathecal clonidine, (21.4 micrograms/day, Group A) or saline solution (Group B), was administered for 14 consecutive days. For evaluating the neurological damage a neuropathological analysis of the spinal cord was performed by light microscopy. RESULTS: Neurohistopathologic examination of the spinal cord specimens failed to show evidence of neurotoxic damage in either group. CONCLUSIONS: These findings showed that continuous intrathecal administration of clonidine did not produce evidence of histological neurotoxicity; therefore it is possible that continuous administration of intrathecal clonidine might be a safe option for treatment of chronic intractable pain; however, further investigations are necessary for evaluating diverse doses and periods of time, and to define its possible behavioral effects.