Immunohistochemical expression of vascular endothelial growth factor receptors FIt1 and KDR in the endometrium during the estrus cycle in albino rats

Angiogenesis is an important process in endometrial development and embryonic implantation and is regulated through vascular endothelial growth factor [VEGF]; its receptors Flt1 and KDR. This work aimed to study the immunoexpression of VEGF receptors [VEGF-Rs] in the endometrium at different ages and reproductive phases and correlate them with the histological profiles in these phases. Seventy female albino rats were included in this study. They were divided into seven groups of 10 rats each: one group consisted of rats in the prepubertal period at age 4-6 weeks; five groups consisted of rats in the reproductive period at age 6-10 months, which were divided according to estrus cycle phases into proestrus, estrus, metestrus, diestrus, and pregnant groups; and the sixth group consisted of rats in the postmenopausal period at age 15-18 months. The uteri of all rats were removed and processed for staining with H and E and were subjected to immunohistochemical staining for Flt1 and KDR. For morphometric measurements, uterine wall thickness and Flt1 and KDR optical density in the endometrial surface epithelium, glandular epithelium, stromal cells, and endometrial endothelial cells were measured using image analysis. Results were statistically compared. The expression of VEGF-Rs was highest in the pubertal age group with marked expression of these receptors in the proestrus phase followed by the estrus phase. This supports the role of sex hormones, especially the estrogen hormone, in regulating VEGF-R expression. The Flt1 receptor was predominantly expressed in endometrial and stromal cells as well as in blastocysts, whereas the KDR receptor was predominantly expressed in endometrial endothelial cells. Comparison among all groups and then between each two groups revealed statistically significant differences in the measured morphometric parameters. The upregulation of Flt1 and KDR could be involved in the regulation of endometrial endothelial cell proliferation and in increase in endometrial vascular permeability, especially at implantation sites

Neuroprotective effect of melatonin in a rat model of streptozotocin-induced diabetic neuropathy: Light and electron microscopic study

Diabetes mellitus [DM] is the most common cause of peripheral neuropathy in most countries. Oxidative stress appears to be the most important pathogenic factor in underlying diabetic complications, including neuropathy. The present study aimed to investigate the possible neuroprotective effects of melatonin [MLT] in a rat model of streptozotocin [STZ]-induced diabetic neuropathy. Thirty-six [15 weeks old] adult male albino rats were divided into three groups. Group I [n=6] served as the control group. In group II [n=15], DM was induced by a single intraperitoneal injection of STZ at a dose of 60 mg/kg body weight and rats were sacrificed after 6 weeks. Rats in group III [n=15] were rendered diabetic by a single intraperitoneal injection of STZ, and immediately after confirmation of DM, that is, 48 h after STZ [random blood sugar > 200 mg/dl], rats received MLT at a dose of 10 mg/kg/day by intraperitoneal injection for 6 weeks. Body weight and random blood sugar were measured for all groups. Sciatic nerves of all the sacrificed animals were subjected to light microscopic, electron microscopic, and morphometric studies. In group II, DM induction was associated with the occurrence of neuropathy manifested by marked thickening of the epineurium and perineurium. Nerve fibers exhibited marked axonal atrophy, axonal shrinkage, axon-myelin separation, and in some sections total axonal destruction. Severe demyelination with evidence of myelin destruction was observed in the form of splitting and decompaction of myelin sheath lamellae, as well as vacuolization of the myelin sheath, forming fermentation chambers. In the MLT-treated group, vacuolization of the myelin sheath decreased remarkably and mild local axon separation from myelin sheaths was detected. Morphometric analysis revealed a significant increase in the number of total and apparently normal fibers and decrease in the number of apparently degenerated fibers in the nerve sections of MLT-treated rats, compared with nontreated diabetic rats. This study showed that MLT, in early stages of DM induction, decreased the destructive progress of DM and provided neuroprotection against damage resulting from STZ-induced hyperglycemia. Thus, it is recommended to start MLT therapy as soon as diagnosis of DM is established and even earlier in individuals at high risk for developing DM

Role of mesenchymal stem cell therapy in restoring ovarian function in a rat model of chemotherapy-induced ovarian failure: a histological and immunohistochemical study

Chemotherapeutic treatment of breast cancer in women causes damage to the reproductive system, which might result in premature ovarian failure [OF]. The present study was carried out to examine the role of mesenchymal stem cell [MSC] transplantation on ovarian function using a rat model of chemotherapy-induced OF. Twenty-six adult female albino rats were divided into two groups. Group I served as the control group. In group II, OF was induced by injecting rats with cyclophosphamide intraperitoneally with an initial loading dose of 50 mg/kg, followed by a dose of 8 mg/kg every 2 weeks for two doses by an intrape-itoneal [IP.] injection. In subgroup I la, rats received cyclophosphamide therapy for 1 month. They were left untreated for a further 1 month [OF nontreated] and were sacrificed 2 months from the start of the experiment. The rats of subgroup lib were injected with MSCs after induction of OF and were sacrificed 1 month after stem cell therapy, that is 2 months from the start of the experiment. Vaginal smears were performed and hormonal profile of serum estradiol [E2], follicle stimulating hormone [FSH], and lutenizing hormone [LH] was measured. Ovarian sections were subjected to H and E, Masson's trichrome, MSC marker CD44, and proliferating cell nuclear antigen [PCNA] immunostaining. The mean number of primordial follicles, mean area% of collagen fibers, mean number of CD44 immunopositive cells, and the mean area% of positive immunoreactivity for PCNA were measured using image analysis. The results were compared statistically. After exposure to chemotherapy, depletion of primordial follicles was observed, with the presence of many atretic follicles, congested blood vessels, and marked cortical fibrosis. Only some of the surface epithelial cells showed PCNA immunoreactivity. After MSC therapy, several primordial follicles were found in addition to secondary follicles and several corpora lutea. PCNA immunoreactivity was detected on the surface epithelium, superficial cortical oocytes, and oocytes of primordial follicles. A significant decrease in the collagen fiber content was observed. MSC transplantation could ameliorate ovarian function in rats with chemotherapy-induced OF

Histological and immunohistochemical study on the protective effect of Ginkgo biloba extract against glutamate-induced neurotoxicity in male albino rat retinal cells

Monosodium glutamate [MSG] has a flavor-enhancing effect; hence, it is added to processed food. It is known for its neurotoxicity. This study was conducted to demonstrate the possible protective effect of the natural antioxidant, Ginkgo biloba extract, against the neurotoxicity of MSG on the retinal cells of male albino rats. Thirty adult male albino rats were used. The animals were divided into the following groups: group I was the control group and group II was subdivided into subgroup IIa, which received MSG injections for 7 days, and subgroup IIb, which received Ginkgo biloba [EGb 761] orally for 7 days and then received MSG injections, in addition to EGb. Retinal sections were stained with H and E stain, toluidine blue stain, and immunohistochemical staining for glial fibrillary acidic protein [GFAP]. Total retinal thickness, thickness of the outer nuclear layer, and the mean area% of GFAP were measured using an image analyzer. MSG caused complete loss of the outer and inner segments of the photoreceptors, a decrease in the thickness of the outer nuclear and plexiform layers, focal cytoplasmic vacuolation in the inner nuclear layer, and complete distortion of the ganglion cell layer. Such abnormalities were, to a large extent, prevented with the use of EGb 761. Statistically significant differences in the total retinal thickness, the thickness of the outer nuclear layer, and mean area% of GAP were found between the groups. MSG exposure was shown to induce deleterious morphological changes on the retina, many of which were prevented with the use of EGb 761. Thus, this natural extract could have further clinical implications in reducing glutamate-induced excitotoxicity in several ophthalmic diseases