Effects of Ovariectomy and Exercise Training on Mineral Status in a High-Fat Diet-Induced Obesity Rat Model.

Osteoporosis is a growing public health issue for an aging society. Previous studies have found both beneficial and detrimental effects of obesity on bone health. The purpose of this study was to investigate the impact of estrogen deficiency and physical activity on bone and blood concentrations of macrominerals (Ca, P, and Mg) and microminerals (Zn, Se, Cu, and Fe) in a high-fat diet-induced obesity rat model. Forty-eight female Wistar rats were divided into six groups: sham-operated and ovariectomized rats that received a standard diet (SD), high-fat diet (HFD), or HFD accompanied by physical exercise. The effect of ovariectomy on bone minerals varied with diet. Ovariectomy significantly decreased femoral Ca and Mg in sedentary rats receiving a SD; femoral Se, Cu, Zn, and Fe in sedentary rats on HFD; and plasma Fe in both sedentary rats on SD and exercising rats on HFD. The interaction of ovariectomy and diet had the strongest impact on Mg and Se concentrations in femur. In ovariectomized rats, HFD showed to have a protective effect on bone mineralization (femoral Ca and Mg), and a negative one on antioxidant microminerals (femoral Se, Cu, and Zn). Physical activity reduced the decline of Se, Cu, Zn, and Fe in the femur of ovariectomized rats on HFD. In the current state of knowledge, it is difficult to suggest if decreased femoral levels of antioxidant microminerals may contribute to the pathophysiology of osteoporosis in obese individuals or just reflect the mineral status in the body.

Impact of ovariectomy, high fat diet, and lifestyle modifications on oxidative/antioxidative status in the rat liver.

AIM: To estimate the impact of high fat diet and estrogen deficiency on the oxidative and antioxidative status in the liver of the ovariectomized rats, as well as the ameliorating effect of physical activity or consumption of functional food containing bioactive compounds with antioxidative properties on oxidative damage in the rat liver. METHODS: The study was conducted from November 2012 to April 2013. Liver oxidative damage was determined by lipid peroxidation levels expressed in terms of thiobarbituric acid reactive substances (TBARS), while liver antioxidative status was determined by catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR) activities, and glutathione (GSH) content. Sixty-four female Wistar rats were divided into eight groups: sham operated and ovariectomized rats that received either standard diet, high fat diet, or high fat diet supplemented with cereal selenized onion biscuits or high fat diet together with introduction of physical exercise of animals. RESULTS: High fat diet significantly increased TBARS content in the liver compared to standard diet (P=0.032, P=0.030). Furthermore, high fat diet decreased the activities of CAT, GR, and GST, as well as the content of GSH (P<0.050). GPx activity remained unchanged in all groups. Physical activity and consumption of cereal selenized onion biscuits showed protective effect through increased GR activity in sham operated rats (P=0.026, P=0.009), while in ovariectomized group CAT activity was increased (P=0.018) in rats that received cereal selenized onion biscuits. CONCLUSION: Feeding rats with high fat diet was accompanied by decreased antioxidative enzyme activities and increased lipid peroxidation. Bioactive compounds of cereal selenized onion biscuits showed potential to attenuate the adverse impact of high fat diet on antioxidative status.

Effects of high fat diet, ovariectomy, and physical activity on leptin receptor expression in rat brain and white fat tissue.

AIM: To evaluate in a rat animal model whether ovariectomy, high fat diet (HFD), and physical activity in the form of running affect leptin receptor (Ob-R) distribution in the brain and white fat tissue compared to sham (Sh) surgery, standard diet (StD), and sedentary conditions. METHODS: The study included 48 female laboratory Wistar rats (4 weeks old). Following eight weeks of feeding with standard or HFD, rats were subjected to either OVX or Sh surgery. After surgery, all animals continued StD or HFD for the next 10 weeks. During these 10 weeks, ovariectomy and Sh groups were subjected to physical activity or sedentary conditions. Free-floating immunohistochemistry and Western blot methods were carried out to detect Ob-R in the brain and adipose tissue. RESULTS: StD-ovariectomy-sedentary group had a greater number of Ob-R positive neurons in lateral hypothalamic nuclei than StD-Sh-sedentary group. There was no difference in Ob-R positive neurons in arcuatus nuclei between all groups. Ob-R distribution in the barrel cortex was higher in HFD group than in StD group. Ob-R presence in perirenal and subcutaneous fat was decreased in StD-ovariectomy group. CONCLUSION: HFD and ovariectomy increased Ob-R distribution in lateral hypothalamic nuclei, but there was no effect on arcuatus nuclei. Our results are first to suggest that HFD, ovariectomy, and physical activity affect Ob-R distribution in the barrel cortex, which might be correlated with the role of Ob-R in election of food in rats.

HIV and risk behaviour among men who have sex with men in Slovakia (2008-2009).

The HIV infection remains a major public health issue in the world and especially in those countries where there exists unprotected sexual intercourse between people of the same sex. It is namely the category of men having sex with men (MSM) that still represents a group at high risk of being infected with HIV or transmitting the virus. The aim of our study was to present HIV 2nd generation surveillance data on MSM in Slovakia in the period between the years 2008 and 2009. Time-location sampling (TLS) was used to recruit participants and oral fluid samples together with completed anonymous questionnaires were collected simultaneously. The oral fluids were tested with use of the Genscreen HIV ½ version 2, (Bio-Rad) and Western Blot (Genlabs) diagnostic kits. The data analysis was performed using Stata version 8. Saliva testing revealed HIV prevalence of 6.1% (21/349) among MSM in Slovakia. 75% of HIV-positive cases were undiagnosed. The high-risk behaviour of MSM in respect to the number of their sexual partners as well as drug and condom usage did not correspond with their relatively high knowledge about HIV/AIDS. People's attitude towards MSM was found to be the worst in the religious context. Though our results reflect a relative good knowledge of MSM about HIV/AIDS infection, new HIV-positive cases and high-risk behaviour still appear, suggesting the need for more effective HIV prevention among members of this high-risk group in Slovakia.