Hyperglycemia decreased medial amygdala projections to medial Preoptic area in experimental model of diabetes mellitus

In Wistar rats, reproductive behavior is controlled in a neural circuit of ventral forebrain including the medial amygdala (Me), bed nucleus of the stria terminalis (BNST) and medial preoptic area (MPOA) via perception of social odors. Diabetes Mellitus (DM) is a widespread metabolic disease that affects many organs in a variety of levels. DM can cause central neuropathies such as neuronal apoptosis, dendritic atrophy, neurochemical alterations and also causes reproductive dysfunctions. So we hypothesized damage to the nuclei of this circuit can cause reproductive dysfunctions. Therefore in this project we assessed diabetic effect on these nuclei. For this purpose neuron tracing technique and TUNEL assay were used. We injected HRP in the MPOA and counted labeled cells in the Me and BNST to evaluate the reduction of neurons in diabetic animals. Also, coronal sections were analyzed with the TMB histochemistry method. Animals in this study were adult male Wistar rats (230 ± 8g) divided to control and 10-week streptozotocin-induced diabetic groups. After data analysis by SPSS 16 software, a significant reduction of HRP-labeled neurons was shown in both Me and BNST nuclei in the diabetic group. Moreover, apoptotic cells were significantly observed in diabetic animals in contrast to control the group. In conclusion, these alterations of the circuit as a result of diabetes might be one of the reasons for reproductive dysfunctions. © 2015 Tehran University of Medical Sciences. All rights reserved

The Effects of Nitric Oxide on Volume, Weight and Histology of Pregnant, S Rat Heart

Backgrounds: Nitric oxide (NO) as a lipophilic small molecule is produced from L- Arginine by a family of Nitric oxide Synthase (NOS) enzymes in living organisms. Objective: NO is now recognized as an important signaling molecule involved in a wide range of physiological and pathophysiological processes including cell growth, apoptosis and immunological regulation. The aim of this study is investigation of Nitric oxide effects on Volume, Weight and Histology of Pregnant, s rat Heart. Material &Methods: Forty female Wister rats, weighing 200- 250 gr with a mean age of 8 weeks, were divided into 5 groups (n=8) after making sure that the experimental rats were pregnant. The first group was received 2mg/kg normal saline and the others were received respectively 200mg/kg L-Arginine, 20mg/kg L-NAME and a mixture of the same doses of L-Arginine & L-NAME on 3, 4 and 5th gestational days via intraperitoneal. The control group was not received any injection. Hearts were removed on 18th gestational days, then after weight and volume measuring and tissue preparation via staining by routine H&E methods studied by Light microscopy. Results: Despite the increasing in weight and volume of the L-NAME group, there were no significant differences between groups but most histological changes in L-NAME group were observed. Conclusion: We found that L-NAME in pregnancy can cause histopathological changes in heart tissue via decreasing levels of NO

Melatonin in cryopreservation media improves transplantation efficiency of frozen-thawed spermatogonial stem cells into testes of azoospermic mice

Background Cryostorage of spermatogonial stem cells (SSCs) is an appropriate procedure for long-term storage of SSCs for fertility preservation. However, it causes damage to cellular structures through overproduction of ROS and oxidative stress. In this study, we examined the protective effect of melatonin as a potent antioxidant in the basic freezing medium to establish an optimal cryopreservation method for SSCs. Methods SSCs were obtained from the testes of neonatal male mice aged 3-6 days. Then, 100 mu M melatonin was added to the basic freezing medium containing DMSO for cryopreservation of SSCs. Viability, apoptosis-related markers (BAX and BCL2), and intracellular ROS generation level were measured in frozen-thawed SSCs before transplantation using the MTT assay, immunocytochemistry, and flow cytometry, respectively. In addition, Western blotting and immunofluorescence were used to evaluate the expression of proliferation (PLZF and GFR alpha 1) and differentiation (Stra8 and SCP3) proteins in frozen-thawed SSCs after transplantation into recipient testes. Results The data showed that adding melatonin to the cryopreservation medium markedly increased the viability and reduced intracellular ROS generation and apoptosis (by decreasing BAX and increasing BCL2) in the frozen-thawed SSCs (p < 0.05). The expression levels of proliferation (PLZF and GFR alpha 1) and differentiation (Stra8 and SCP3) proteins and resumption of spermatogenesis from frozen-thawed SSCs followed the same pattern after transplantation. Conclusions The results of this study revealed that adding melatonin as an antioxidant to the cryopreservation medium containing DMSO could be a promising strategy for cryopreservation of SSCs to maintain fertility in prepubertal male children who suffer from cancer