FERTILITY INDICATORS AND PLASMA LEPTIN LEVELS IN RATS UNDER THE INFLUENCE OF HIGH-CALORIES DIETS
DOI:
https://doi.org/10.11603/mcch.2410-681X.2021.i4.12734Keywords:
leptin, obesity, high-calorie diets, fertilityAbstract
Introduction. The molecular mechanisms underlying the relationship between obesity to male fertility are being actively studied by the scientific community. Leptin is a peptide hormone that is mainly synthesized in adipose tissue and maintains energy homeostasis. In addition, it is actively involved in the regulation of reproductive function through modulation of the hypothalamic-pituitary-gonadal axis. Probably, leptin can be considered as a biomarker that combines metabolic status with the reproductive system of the body.
The aim of the study – to evaluate the effect of high-calorie diets on male fertility and plasma leptin levels.
Research Methods. The study was performed on 30 white nonlinear male rats weighing 250–300 g, which were divided into three groups, 10 males each: the control group of rats (CG) consumed standard food; animals of the experimental groups received a high-fat diet (HFD) and a high-fat/high-sugar diet (HFHS), respectively. The animals were kept on these diets for seven weeks. After euthanasia, morphometric measurements were performed, Lee index, testicular coefficient and visceral fat coefficient were calculated. Blood for the study was taken from the rat tail vessels in eppendorf with heparin. The material was centrifuged at 800 g for 5 min, then plasma was collected for further studies. Sperm suspension was prepared from the cauda epididymis. The total number of sperm cells and motility were calculated. Sperm vitality were performed by staining of spermatozoa with propidium iodide, and fluorescence was assessed using an Olympus IX73 microscope. The concentration of leptin in blood plasma was determined by enzyme-linked immunosorbent assay.
Results and Discussion. Keeping rats on HFD and HFHS by 7 weeks did not significantly affect body weight gain. The Lee index did not differ significantly between the study groups (p=0.59). However, the coefficient of visceral fat in the HFHS group was 40 % higher compared to CG (p=0.04). We did not find a significant difference between the experimental groups in terms of sperm count (p=0.72), motility (p=0.63) and viability (p=0.87). A diet with high sugar and fat resulted in a 14 % increase in leptin plasma concentrations in rats versus baseline (p=0.01).
Conclusions. Short-term high-fat/high-sugar diet causes metabolic changes, as evidenced by a significant increase in the proportion of adipose tissue and plasma leptin levels.
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