Teratogenic effects of indomethacin on rat embryos

In this study 16 pregnant albino rats was divided into two eaual groups. The first group was injected daily with 1 mg/kg body weight indomethacin intraperitoneally from day 6 to 10 of gestation. Doses of 2 mg/kg body weight or more were tried but were rejected because of high incidence of embryolethality and maternal mortality. One da 12 of gestation [11.5 embryonic age day], embryos were explanted, examined and their morphological parameters were evaluated. The most common development effect observed in embryos of the treated group was intrauterine growth retardation as evidenced by the significant decrease in their morphological score when comared with those of the control group. In embroys of the treated group, there were a decrease in both crown-rump and head lengths, reduction in the numbers of both branchial bars and somites, as well as a delay in the formation of the forelimb bods. Also a significant increase in embryolethality was was noticed in the treated group as proved by the increased number of resorptions. These changes were associated with a decrease in the body weight of the treated mothers when comared with the control ones. On the basis of the findings of the present study, it can be concluded that malnutrition of the pregnant rats caused by gastrointestinal tract dysfunction, constriction of the vessels of the conceptus, viz. uterine, umbilical and vitelline vessels and impariment of cell division of the embryo may contribute in the mechanisms through which indomethacin could affect the rat embryos

effect of proximal versus distal circumferential periosteal release on the rate of growth of the growing and of the tibia: an experimental study in albino rats

Twenty albino rats, each aged 4 weeks and weighting 50-60 gms, were used in this study. They were divided into two groups, each group consisted of 10 rats [five males and five females]. Unilateral tibial circumferential periosteal release was performed proximally in the first group and distally in the second group. In all cases, the periosteum of the shaft was incised 3-4 mm away from the growth plate. X-ray imaging was performed at weekly intervals starting from the day of surgery till the 14th week. Tibial length either on the operated or the control sides was measured for each animal from the X-ray films. The growth zone of the growing end of each tibia was examined microscopically. The surgery was followed by a latent period of two weeks in the first group and three weeks in the second group. During this latent period, there was no observable difference in the growth rates between the operated and control sides. Thereafter, the rate of growth of the side of operation exceeded that of the control side. In the subsequent two weeks, the rate slowed down. By the 14th week, tibiae of proximal periosteal release showed an increase of about 14% more than the control ones, while the corresponding increase in distal release was only 6.3%. Microscopic examination of the proximal epiphyseal plate of the tibiae revealed marked widening of the growth zone in the bibiae of the operated sides compared to the control ones especially in the cases of proximal periosteal release. In can be concluded that proximal circumferential perisoteal release can serve as a reliable and safe means of growth stimulation of the long bones of the growing animal and that can be applied for leg-length inequality. The site of the operation and the age of the child should be put into consideration. The response is inversely proportional to the age and it is more manifest in proximal than distal release