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Regulation of Blood Glucose
Published in Robert B. Northrop, Endogenous and Exogenous Regulation and Control of Physiological Systems, 2020
Elevated leptin also decreases the rate of neuropeptide Y (NPY) release from hypothalamic neurosecretory cells in the brain. Thus there are at least two negative feedback loops regulating leptin secretion, leptin/insulin and leptin/NPY. Although the regulated variable appears to be leptin, leptin controls the average dietary calorie input through NPY. Excess calories over time, if not balanced by metabolic loss due to exercise, certainly lead to excess fat, as we all know. Hypothalamic NPY is reported to stimulate hunger and eating behavior and hence caloric intake. It also stimulates the secretion of insulin, although this stimulation may be indirect. NPY is also found in large vesicles in the endings of sympathetic nerve fibers in the body. NPY from this source evidently acts as a potent, long-acting vasoconstrictor, having synergistic action with norepinephrine.61 These dual actions of NPY are a good example of hormonal pleiotropy.
Applications of Biomaterials in Soft Tissue Replacement
Published in Yaser Dahman, Biomaterials Science and Technology, 2019
Fat tissues, also known as adipose tissues, are composed of lipid filled cells referred to as adipocytes, along with fibroblasts and immune cells. They have an extensive network of collagenous extracellular matrices (ECM) that are infiltrated by blood vessels (Alkhouli, 2013). Adipose tissue can be found all over the body and are responsible for cushioning and protecting organs and structures, thermal insulation, as well as the storage of surplus triglycerides to be used as energy. Adipose tissue is a connective tissue that is characterized by high expandability, which is proportional to obesity. Triglycerides make up the majority of the volume of adipose tissue as well as approximately 85% of the tissue’s weight (Alkhouli, 2013). Levels of collagen in adipose vary depending on the expandability of the tissues. Not many studies out there examine the mechanical properties of adipose tissue; most research seems to be focused on the behavioural side of adipose tissue when it undergoes expansion or compression (Alkhouli, 2013).
Alkaloids potential health Benefits and toxicity
Published in Quan V. Vuong, Utilisation of Bioactive Compounds from Agricultural and Food Waste, 2017
Renée A. Street, Gerhard Prinsloo, Lyndy J. McGaw
Obesity is a complex chronic condition in which excess body fat accumulates into adipocytes, leading to adverse metabolic effects on blood pressure, cholesterol, an increased risk for type 2 diabetes T2DM, coronary heart disease and hypertension (Choi et al. 2014, WHO 2016). In obesity, there is an increase in the number of differentiated mature cells, which are regulated by genetic and environmental factors. The prevalence of obesity has been increasing in both the developed and developing world (Choi et al. 2014). In 2014, nearly 2 billion adults worldwide were overweight (39 per cent of adults 18+) and, of these, more than half a billion were obese. In Americas, Europe and Eastern Mediterranean regions, 50 per cent of women are overweight and 25 per cent of these are obese. Obesity is, however, more prevalent in low and lower middle-income countries with more women obese than men (WHO 2016). Screening natural products for anti-obesity potential is important in the search for treatment of this worldwide disease (Choi et al. 2014). The fruits of Piper retrofractum have been used for their anti-flatulent, expectorant, antitussive, antifungal and appetizing properties in traditional medicine, and they are reported to possess gastroprotective and cholesterol-lowering properties. Piperidine alkaloids from Piper retrofractum, namely piperine, pipernonaline and dehydropipernonaline were isolated as anti-obesity constituents of this plant (Kim et al. 2011).
Continuous walking and time- and intensity-matched interval walking: Cardiometabolic demand and post-exercise enjoyment in insufficiently active, healthy adults
Published in Journal of Sports Sciences, 2021
Kate Francis, Tom Williamson, Paul Kelly, Shaun M. Phillips
There was a large negative difference in fat utilisation in IW vs CW. On first consideration, these metabolic responses do not favour IW as a method of body fat loss when considering the positive impact of exercise at maximal fat oxidation intensity on body composition (Tan et al., 2016). However, a recent systematic review found that HIIE elicits similar reductions in body fat percentage, and larger reductions in absolute fat mass than MICE (Viana et al., 2019). The positive effect of HIIE on body composition may be due to greater short- and longer-term post-exercise resting energy expenditure and therefore fat oxidation (Skelly et al., 2014). However, specific mechanisms likely depend in part on the intensity of the HIIE protocol. Nevertheless, these findings show that meaningful reductions in body fat are achievable via exercise that is sub-optimal for in-exercise fat metabolism. It is unlikely that the IW or CW protocol would result in prolonged elevations in resting energy expenditure. Coupled with the modest reduction in fat expenditure in IW vs. CW (~20 kcal), it is unlikely that differences in substrate use between trials would meaningfully influence body composition changes. Therefore, reduced fat metabolism in IW should not be viewed as a negative characteristic.
New approaches towards the discovery and evaluation of bioactive peptides from natural resources
Published in Critical Reviews in Environmental Science and Technology, 2020
Nam Joo Kang, Hyeon-Su Jin, Sung-Eun Lee, Hyun Jung Kim, Hong Koh, Dong-Woo Lee
Accumulation of excess body fat causes obesity, exerting a negative effect on health. The amount of adipose tissue tightly regulated by adipogenesis in pre-adipocyte cells, the best-characterized model for studying adipogenesis (Aoyama, Fukui, Takamatsu, Hashimoto, & Yamamoto, 2000). Glycerol-3-phosphate dehydrogenase (GPDH), a key enzyme in glycolysis, is linked to phospholipid and triglyceride biosynthesis (Harding, Pyeritz, Copeland, & White, 1975; Tsou, Lin, Lu, Tsui, & Chiang, 2010). Because suppression of GPDH activity inhibits differentiation and reduces lipid accumulation in pre-adipocyte cells, the anti-adipogenic effects of BPs can be evaluated by measuring the activity of this enzyme (Hirai, Yamanaka, Kawachi, Matsui, & Yano, 2005). In addition, saturated fatty acids from acetyl-CoA and malonyl-CoA are synthesized endogenously by fatty-acid synthase (FAS), which is involved in adipogenesis (Leibundgut, Maier, Jenni, & Ban, 2008). Some hydrolyzed proteins can inhibit FAS activity, thereby controlling cell differentiation and lipid accumulation (Gonzalez-Espinosa de los Monteros, Ramon-Gallegos, Torres-Torres, & Mora-Escobedo, 2011; Martinez-Villaluenga, Dia, Berhow, Bringe, & Gonzalez de Mejia, 2009).
Higher socioeconomic status is related to healthier levels of fatness and fitness already at 3 to 5 years of age: The PREFIT project
Published in Journal of Sports Sciences, 2019
Ignacio Merino-De Haro, Jose Mora-Gonzalez, Cristina Cadenas-Sanchez, Pere A. Borras, Pedro J. Benito, Oscar Chiva-Bartoll, Coral Torrijos-Niño, Cristina Samaniego-Sánchez, José Javier Quesada-Granados, Alejandro Sánchez-Delgado, Cecilia Dorado-García, José M. García-Martínez, Germán Vicente-Rodríguez, Idoia Labayen, Francisco B. Ortega
Childhood obesity is one of the most serious public health problems of the 21st century (World Health Organization [WHO], 2015). An excess of body fat has severe health consequences for children, making them more likely to develop diabetes or cardiovascular diseases or to have a premature death later in life (GBD 2015 Obesity Collaborators, 2017; Lavie, McAuley, Church, Milani, & Blair, 2014; Ortega, Lavie, & Blair, 2016). Likewise, physical fitness components (i.e. cardiorespiratory fitness, speed/agility, and musculoskeletal fitness) are considered important health-related markers already in youth, and may serve as potential protectors to reduce the harmful effects of fatness on health (Ortega, Ruiz, Castillo, & Sjöström, 2008; Ruiz et al., 2009).