Teratologieal effects of gamma-irradiation during three gestaional intervals in rats

The present study aimed to evaluate the teratological effects of gamma-irradiation during three intervals of gestation; pre-implantation, organogenesis and fetal periods in rats. Four groups of pregnant rats were used in this study; the first one [GI] served as control. The second [GII], third [GIII] and fourth [GIV] groups were subjected to whole body gamma-radiation at a sub-lethal single dose level of 4 Gy at the third day, 10[th] day and 14[th] day of gestation respectively. Pregnant rats were sacrificed at the 20[th] day of gestation, implantation sites, resorption, embryonic death, fetal death, growth retarded fetuses, external malformations and skeletal malformiation were recorded. The results showed that whole body gamma-irradiation caused resorption in the embryos of pregnant rats especially in those exposed during the pre-implantation period than the two other periods. The embryonic and fetal deaths were prominent in the fetuses maternally exposed to whole body gamma-irradiation during the organogenesis period. The highest percentage of growth retarded fetuses was found in fetuses maternally exposed to gamma-rays during the organogenesis period followed by fetuses maternally exposed to gamma-irradiation during the fetal period and then fetuses maternally exposed to gamma-irradiation during the pre-implantation period. The skeletal malformations as a result of gamma-irradiation were mostly represented in less ossification in the skull bones, less ossification in the vertebral centra and wavy ribs. The most affected fetal skeleton was perceptive in GIII [fetuses maternally exposed to gamma-irradiation during the organogenesis period] followed by GIl and then GIV

Effects of melatonin on the teratogenicity of alcohol in albino rat

Teratogenicity of alcohol has been widely studied in humans and laboratory animals. Alcohol seems to produce its deleterious effects through its capability to release harmful free radicals. The aim of the present study was to determine the potential role of exogenous melatonin as a free radical scavenger [antioxidant] against the teratogenicity of alcohol. Twenty four pregnant albino rats were randomly divided into four equal groups: control, alcohol, melatonin and melatonin-alcohol. Treatment was given intragastrically daily from day 6 through day 12 of gestation. Twenty days full term rat fetuses were then collected. Two thirds of the fetuses were fixed in Bouin's solution for external and visceral examinations. Skeletons of the remaining third of the fetuses were stained with alizarin red for their evaluation. The present study revealed the teratogenicity of alcohol even in its mild dose of 15 ml/kg BW [ethanol, 25% v/v]. In the experimental rats, it increased the rate of resorptions and delayed the fetal growth. It also affected the ossification of the skeletal system and produced different congenital abnormalities. Exogenous melatonin given in this study in a dose of 9 mg/kg BW did not affect significantly the fetal growth and development and did not produce any congenital abnormalities. However, all developmental parameters assessed in this study were found to be normal in the melatonin-alcohol group when compared to the control group. Also, no congenital abnormalities were detected. The results obtained from this study indicate that melatonin probably acts as a negative coteratogen as it counteracts the teratogenic effects of alcohol. The present results also support those reported by previous workers which indicated the role of free radicals in mediating the teratogenicity of alcohol. According to the present findings, it is suggested that any substance known to release free radicals should be prohibited during pregnancy. If it is necessary, it should be combined with a potent antioxidant, to avoid its teratogenic effects

Effect of exercise during pregnancy and dam age on maternal blood chemistry and fetal growth

in order to determine the effect of maternal exercise on maternal nutritional status and fetal growth, young (Y=45-50 days old) Wistar rats were divided into 4 groups of 5 to 8 animals: control pregnant (CP), control non-pregnant (CNP), exercise-trained (swimming 1 j/day, 5 days/week, for 19 days) pregnant (TP) and exercise trained non-pregnant (TNP). Four equivalent groups of adult rats (A=90-100 days old) were also formed. Serum glucose, total protein, albumin, hematocrit and liver glycogen were determined in female rats and pups. There were no statistical differences in serum glucose, total protein and albumin levels, litter size or birth weight among exercise-trained animals, controls and their respective pups. Hematocrit was significantly lower in pups of exercise-trained young and control rats of the same age and physiological status (YCNP+4.1 ñ 0.2; YCP = 2.7 ñ 0.9; YTNP + 4.9 ñ 0.8; YTP = 2.7 ñ 0.4; ACNP = 6.1 ñ 0.6; ACP = 3.1 ñ 0.8; ATNP = 6.6 ñ 0.8; ATP = 2.2 ñ 0.9 mg/100 mg). We conclude that pups of adult female rats are spared from the effects of this kind of exercise training during pregnancy. On the other hand, it appears that maternal adaptations to exercise training in young rats are able to preserve only some aspects of pup metabolism