Post-operative time effects after sciatic nerve crush on the number of alpha motoneurons, using a stereological counting method [dissector]

There are extensive evidences that show axonal processes of the nervous system [peripheral and/or central] may be degenerated after nerve injuries. Wallerian degeneration and chromatolysis are the most conspicuous phenomena that occur in response to injuries. In this research, the effects of postoperative time following sciatic nerve crush on the number of spinal motoneurons were investigated. Twelve adult male Wistar rats, whose left sciatic nerves were highly compressed for 30 s, assigned to experimental groups 1 and 2 [n = 6]. After 3 and 8 weeks post-operative [in groups 1 and 2 respectively] the lumbar segments of spinal cord were sampled, processed, sectioned serially and stained with toluidine blue [pH 4.65]. By using stereological quantitative technique [physical disector], the number of alpha motoneurons in the right and the left ventral horns of spinal cord were counted and compared with each other. Statistical analyses showed a remarkable reduction in the number of alpha motoneurons in the left side [experimental or operated] when compared with the right side [control or unoperated] both in 3 and 8 weeks post-operative groups. This reduction may be due to the blockade of retrograde axonal transport

abortional and the teratogenical effects of 17 - beta estradiol valerate administration during embryonic development in rats

Among the female sexual hormones, the estrogen and progesterone are of significant importance. These hormones are prescribed for the treatment of certain female genital system disorders as well as used in the synthesis of contraceptive drugs. It has been shown that administration of the above hormones during early pregnancy may produce abortion in early gestational days. In the present investgation, we have studied the possible abortional and teratogenical effects of a single intramuscular injection of 0.15 mg/kg esteradiol valerate during the first or second half of pregnancy, in rats. The data show that; [1] The abortional effects of administration of esteradiol during the first half of pregnancy, in comparison with the control group, is significant. Although the injection of this hormone during the second half of pregnancy does not produce total abortion but there is a reduction in the number of fetuses. Therefore, it may be said that with injection of a single dose of hormone during the first half of pregnancy [from day zero to day 10] the chance of abortion is high [in human embryos, this period is about the first four weeks of development]. [2] Administration of estradiol may also produce severe fetal abnormalities such as anencephalia, exencephalia, microphthalmia. In addition to the above abnormalities, in the male fetuses, there is also a remarkable defect in the urogenital system