Effect of High dose Gonadotropin Stimulation on Follicular Atresia through Light Chain 3B and Voltage Dependent Anion Channel 2.

Background: Follicle development takes place under the control of hormonal and environmental stimuli. It suggested that to improve in vitro fertilisation outcomes in poor responders increasing gonadotropin doses be used. Excessive gonadotropin leads to atresia and impairs follicular development, but the molecular mechanisms of follicular atresia remain largely unknown. Recently, it was suggested that autophagy may be an alternative mechanism involved in follicle depletion. Aims: In this study, we aimed to clarify the role of autophagic markers such as light chain (LC) 3B and voltage dependent anion channel 2 (VDAC2) in follicular atresia using the high dose gonadotropin stimulation. Settings and Design: The female 24 BALB/c mice were employed in the present study under the Committee for the Purpose of Control and Supervision of Experiments on Animals guidelines with ethical clearance from the institutional ethical committee. These mice were categorised into four groups, with six rats in each as control and test animals. Materials and Methods: Group 1 (control): no action will be taken. Group 2 (sham): only saline will be applied. Group 3: low-dose gonadotropin Pregnant mare's serum gonadotropin (PMSG) + human chorionic gonadotropin (HCG) will be applied. Group 4: high-dose gonadotropin + HCG will be applied. The animals were sacrificed 48 h after the last injection. For all group samples, both protein and mRNAs of the LC3B and VDAC2 were examined by immunohistochemical and reverse transcription-polymerase chain reaction techniques. Statistical Analysis Used: All variables were analysed using GraphPad Prism 8. Kruskal-Wallis t-test and Mann-Whitney U test were used to compare immunohistochemical results; in addition to this, parametric one-way ANOVA test and Shapiro-Wilk test were applied for quantitative polymerase chain reaction statistics. Results: An increased number of atretic follicles were observed in the high-dose gonadotropin + HCG group. LC3B immunoreactivity of the atretic secondary follicles in the high-dose group is higher than in other groups. The expression of VDAC2 protein in the secondary and Graafian follicles and also VDAC2 mRNA in the ovary were more highly expressed in the control and sham groups. The decrease in VDAC2 mRNA level and immunohistochemical expression was remarkable in the low-dose and high-dose follicle-stimulating hormone groups compared to the control and sham groups. Conclusion: In this study, the increased LC3B and decreased VDAC2 expression, which are autophagy markers, were observed in both the gonadotropins groups, so we suggested that high doses of gonadotropins may cause ovarian atresia.

Influence of Radiation Exposure During Radiotherapy. Evidence for the Increase of Versican and Heparin-Binding EGF-like Growth Factor Concentrations.

OBJECTIVE: To investigate the reaction of versican and heparin-binding EGF-like growth factor (HB-EGF) molecule concentrations to acute radiation exposure in normal bladder and rectal tissue samples in order to gain more insight into the effects of cancer radiotherapy. STUDY DESIGN: Four groups with 6 male adult Swiss Albino mice per group were investigated. The mice bladder and rectum tissue samples were subjected to a 10-Gy single-dose radiation exposure in the pelvic region with a Co-60 teletherapy device and investigated 1, 2, and 7 days after radiation exposure, with 1 reference group which was not exposed to radiation. RESULTS: In the immunohistochemical examination of the tissue samples with anti-versican and anti-HB-EGF primary antibodies was observed a statistically significant increase 7 days after radiation exposure. CONCLUSION: The observed increase of versican and HB-EGF concentrations in the normal tissue matrix after radiation exposure may play a role in the side effects of radiotherapy.

Immunohistochemical detection of transforming growth factor-alpha, epidermal growth factor, and vascular endothelial growth factor expression in hyperstimulated rat ovary.

OBJECTIVE: The aim of the present study is to figure out the immunohistochemical expression of transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), and vascular endothelial growth factor (VEGF) in hyperstimulated rat ovaries. METHODS: Twenty Wistar-Albino adult female rats (250-300 g) were taken into the study. The animals were randomly divided into two groups, each containing 10 rats: (i) stimulation group and (ii) control group. In the stimulation group, a stimulation regimen was administered to induce follicular maturity and ovarian hyperstimulation syndrome (OHSS) at the end using a 30-IU follicle-stimulating hormone that was administered subcutaneously for 4 consecutive days, followed by a 30-IU human chorionic gonadotropin on day 5 to induce ovulation. The rats, in the control group, received 0.2 ml of 0.9% NaCl for 5 consecutive days to mimic the conditions of the study animals. At the end of the treatment period, all rats underwent ovariectomy and the sections of ovaries were stained for the TGF-alpha, EGF, and VEGF. RESULTS: The expression of TGF-alpha, EGF, and VEGF in the endothelium, the stroma, the granulosa cells, and the corpus luteum was found to be significantly higher in the stimulated group, compared to that in the control group ( p < 0.05). CONCLUSION: TGF-alpha, EGF, and VEGF are found to have increased in the hyperstimulated ovaries and this finding seems to be involved in the OHSS pathogenesis.

Effect of angiotensin-converting enzyme-inhibiting therapy on the expression of vascular endothelial growth factor in hyperstimulated rat ovary.

OBJECTIVE: To determine the effect of angiotensin-converting enzyme-inhibiting therapy on the expression of vascular endothelial growth factor (VEGF) in the hyperstimulated rat ovary. DESIGN: Experimental study. SETTING: University animal research laboratory. ANIMAL(S): Thirty Wistar albino adult female rats were studied; 20 rats were stimulated with gonadotropins (groups 1 and 2), and 10 were controls (group 3). Ten of the stimulated rats received additional treatment with enalapril (group 2). INTERVENTION(S): At the end of the treatment period, rat ovaries were subjected to immunohistochemical staining with anti-VEGF antibodies. MAIN OUTCOME MEASURE(S): VEGF staining intensity was graded semiquantitatively, and the H-score was calculated by light microscopic examination of the groups. RESULT(S): VEGF expression was found to be significantly higher in the endothelium and stroma in groups 1 and 2 compared with group 3. Although VEGF immunoreactivity was lower in the stimulation regimen plus enalapril group compared with the stimulation regimen-only group, the difference was insignificant. CONCLUSION(S): Enalapril does not seem to have a significant effect on VEGF expression in the hyperstimulated rat ovary. Because angiotensin II exerts its multiple actions via specific receptors, there may be other factors, such as a receptor blockade, that contribute to the VEGF expression.