Summary
Obesity considered as one of the most important risk factors contributing to the overall burden of diseases worldwide. It is the primary and causal element in metabolic syndrome, which is characterized by a cluster of several metabolic disorders such as insulin resistance, type II diabetes, dyslipidemia, and hypertension. It may be caused by modification of diet by means of overconsumption of high fructose diet. The purpose of our study is to determine the impacts of the diet-induced obesity on the metabolic dysfunctions linked to the ovary.
In this study, 30 female albino rats, which were given standard rat chow and tap water ad libitum for 12 weeks, divided to 5 groups, , each group contained 6 rats, control group (received only dimethyl sulfoxide (DMSO) at the last of the 21 consecutive days), LTZ group (daily administration of 1mg/kg of bodyweight at the last of the 21 consecutive days), HF group (rats received 65% of fructose), LF group (rats received 65% of fructose+ daily administration of 1mg/kg of bodyweight at the last of the 21 consecutive days) and LFD group (rats received 65% of fructose+ daily administration of 1mg/kg of bodyweight at the last of the 21 consecutive days+ 120 ng/100 g bodyweight of Vitamin D3 injection onetime per week). The bodyweight of each groups were measured weekly. At the end of the experiment, rats in all groups were dissected; after collecting the blood, the liver and both ovaries were removed. The sera were prepared for the biochemical analysis (serum insulin, serum glucose, homeostatic model assessment (HOMA) index, testosterone, estrogen, follicle stimulating hormone (FSH), liver glutathione (GSH), liver malonaldehyde (MDA), serum MDA, aspartate transaminase (AST), alanine transaminase (ALT) AST and alkaline phosphatase (ALP)). Liver and ovarian tissues were processed and analyzed by classical histology, as well as some morphometrical alterations for ovaries were presented.
Significant increase in bodyweight and serum glucose concentrations were found in HF and LF groups in comparison to control group, hyperinsulinaemia found in rats of the LTZ and LF groups, in addition, LTZ, HF, and LF groups presented a significant elevation in HOMA index, indicated insulin resistance. Hyperandrogenism found in rats of the LTZ, HF and LF groups, with low serum estrogen concentration. Elevations of MDA and low liver GSH as well as alterations in liver functions parameters were found in LTZ, HF and LF groups, No significant change was found in biochemical tests in LFD group. Positive correlation was found between testosterone with each of the bodyweight, insulin and HOMA index, and negative correlation was found between bodyweight and estrogen. Negative correlation was found between GSH with each of the testosterone, insulin and HOMA index, while positive correlation was found between MDA with each of the testosterone, insulin and HOMA index.
The histological features supported the above results, liver sections in HF and LF groups presented interface hepatitis and both microvesicular steatosis and macrovesicular steatosis, while liver sections in LTZ group found with the only microvesicularsteatosis and interface hepatitis, so LTZ, HF, and LFD groups found with the NALFD. In LFD group VitD3 seems to slightly ameliorate the synergistic action of LTZ and HF diet in liver sections.
Morphometrically, the ovaries of the LTZ, HF and LF groups presented no significant changes in number of the preantral, antral, graffian follicles in comparison to control group. However, weight of ovaries and number of corpora lutea significantly decreased in model groups, while diameter of ovaries increased in the LTZ, HF, and LF groups. Polycytics ovaries found in each of the LTZ, HF, and LFD groups, and the number of cystic follicles positively correlated with each of the bodyweight, insulin, testosterone and MDA. No significant changes observed in morphometrical alterations in ovarian sections of rats in LFD groups.
Moreover, histological alterations in ovarian sections in each of the LTZ, HF, and LF groups were approximately similar to each other; they had normal appearance of primordial and primary follicles. Onward the growth, the oocytes and granulosa layers seem to undergo apoptosis, vaculation found among the cells of granulosa layer, as well as vaculation between antrum and granulosa, with the normal appearances of theca layers in growing follicles. The nucleus underwent picknosis and degenerations, in growing and graffian follicles, and disappeared in cystic follicles. No significant changes observed in histolgical alteration in ovarian section of rats in LFD groups.
posted:26-10-2017