Effects of different models of sucrose intake on the oxidative status of the uterus and ovary of rats

Abstract

The aim of the study was to assess the effect of different models of sucrose intake on carbohydrate-lipid metabolism and changes in oxidant balance in the ovaries and uterus of rats. Animals were divided into three groups: I—basic feed, II—feed contains 8% of sucrose, III—alternately every second week the basic feed and modified feed contains 16% of sucrose. The diet containing 8% of sucrose was found to result in an increased activity of antioxidant enzymes in the blood, with unchanged malonylodialdehyde concentration. Variable sucrose administration pattern intensified oxidative stress in the blood and led to disturbed redox equilibrium in the rat uterus, even at a comparable long-term sucrose uptake as in the group II. This was manifested as a reduced superoxide dismutase activity (in the blood and uterus) and a higher malonylodialdehyde concentration (in the uterus). The changes observed could have been a result of metabolic disorders (higher amount of visceral fat, higher glucose concentration, higher index of homeostasis model assessment of insulin resistance, and reduced HDL-cholesterol concentration) and endocrine disorders (higher oestrogen concentrations). Changes in the antioxidant status in the rats kept on the alternating diet, may underpin the failure of fertilised egg implantation in the uterine tissue and pregnancy completion.

The role of oxidative stress in ovarian aging: a review

“…Abundant clinical studies have confirmed that a high-sugar diet can lead to an OS state in the body, which accelerates the development of multisystem pathologies, such as diabetes, neurodegenerative and cardiovascular diseases [108][109][110]. A high-sugar diet, whether long-term, short-term or fluctuating, can affect the body's redox status and thus have a negative impact on ovarian function [111].…”

The Effect of Alternating High-Sucrose and Sucrose Free-Diets, and Intermittent One-Day Fasting on the Estrous Cycle and Sex Hormones in Female Rats

“…That high-sucrose diets reduce LH levels suggests that the effect may be due to, inter alia, factors related to the profile of metabolic disorders that accompany sucrose consumption. We have already shown [ 19 , 20 ] that a high-sucrose diet (HSG and PSG), even when administered periodically (AFG), significantly increases glycemia, the HOMA-IR index, and LDL-cholesterol, and reduces the HDL-cholesterol concentration as compared to the group fed a low-sucrose diet (SBG).…”

“…Moreover, insulin resistance is strongly associated with lower levels of HDL-cholesterol, which modulates glucose metabolism by activating AMP-dependent protein kinase (AMPK) [ 45 ]. Hence, both insulin resistance and the low HDL-cholesterol levels shown in our previous studies in the HSG, AFG, and PSG [ 19 , 20 ] may have contributed to the disruption of the hypothalamic–pituitary axis, including the reduction in LH synthesis and/or secretion [ 46 ]. Insulin is a signal that links metabolism with reproduction, particularly since Kiss1 neurons are sensitive to circulating metabolic signals such as leptin and insulin, which confirms their importance in mediating the body’s response to nutrition or malnutrition [ 47 ].…”

“…Sagae et al [ 53 ], who fed rats cafeteria-style diets, showed a decreased pre-heat LH surge along with reduced Pg levels. The cause for the lower Pg concentrations in HSG, AFG, and PSG could also be due to the low HDL-cholesterol concentration [ 19 , 20 ], which may negatively affect Pg synthesis. In rodents, cholesterol derived from HDL lipoproteins and intercepted from the circulation is the Pg synthesis precursor molecule [ 54 ].…”

“…Our previous studies, in which we used sucrose doses in the amount of 10–18% of the energy value of the diet and made various attempts to reduce its consumption, showed that an increased dietary sucrose content, periodic fasting, or frequent changes in the diet composition (sugar-free vs. high-sugar diet) brought about adverse metabolic changes and increased free-radical reactions in the ovaries and uterus of female rats [ 19 , 20 ]. The demonstrated changes may modify the secretion of sex hormones by the gonads (estrogens and progesterone), also influencing, through a feedback loop, the secretion of luteinizing and follicle-stimulating hormones, and thus the course of the sexual cycle [ 21 ].…”