Determining the Metabolic Effects of Adrenalectomy and Glycemic Parameters on Caloric Efficiency and Adiposity in the Congenic LA/Ntul//-cp (Corpulent) Rat | Chapter 05 | Emerging Trends in Disease and Health Research Vol. 6

 The obese phenotype of the congenic LA/Ntul/-cp (corpulent) rat strain has developed obesity by 6 weeks of age. Congenic male lean and obese LA/Ntul/-cp (corpulent) rats were fed an ad libitum standardised Purina chow diet (CHOW) from 6 to 12 weeks of age, and subgroups (n=6 rats / subgroup) were overfed with a highly palatable cafeteria diet (CAFÉ) to learn more about the role of adrenal cortical secretions in the expression of obesity in this strain's obese phenotype (WOA). A subset of obese rats (n=6) had bilateral adrenalectomy (ADX) at 6 WOA and were given the same feeding and treatment regimen. BW of lean and obese animals were similar at 6 WOA and increased by 88 percent in the lean phenotype and 281 percent in the obese phenotype over the course of the 6-week study, whereas BW of ADX obese rats were similar at 6 and 9 WOA but continued to increase to 2.5-fold above starting weights and 1.8-fold above 9-week weights between 9 and 12 WOA. The CAFE supplement had no effect on final body weights in the lean phenotypes, but was associated with significantly greater body weights in the obese phenotype (p=0.05) at ages 9 and 12 WOA, as well as obese-ADX at 12 WOA. CE (kcal/gram gain in BW per day) remained essentially consistent throughout the trial in both lean and obese-ADX rats, however CE was more efficient in the obese phenotype at all ages tested and with the CAFE supplement feeding regimen. At 12 weeks of age, the obese had a 4.2-fold higher fasting I:G ratio than the lean, which was partially corrected in obese-ADX to a 1.7-fold rise at 12 WOA. Obese rats demonstrated a 3.8-fold higher relative adiposity than lean rats, with the highest increase in the SQ depot. Obese rats showed lower resting VO2 (RMR) than lean rats at all ages tested, which was aided by ADX. In comparison to lean rats, obese and obese-ADX rats exhibit higher thermogenic interscapular brown adipose tissue (IBAT). In conclusion, the findings of this study show that CE is associated with a predisposition for the expression and development of adiposity in this strain's obese phenotype, as well as an increased I:G ratio and IBAT mass, which are consistent with reduced insulin sensitivity and an impaired capacity for energy expenditure, and that CE returned to normal after ADX on the Chow diet but not the CAFE diet. These findings point to a variety of metabolic characteristics that contribute to superior energy storage, utilisation, and/or conservation efficiency in the fat phenotype of this strain compared to the lean phenotype, and that ADX partially corrected in the obese phenotype.

Author(S) Details

Orien L. Tulp
University of Science, Arts and Technology, Montserrat, British West Indies and The University of Health and Humanities, Virgin Islands, UK and The Einstein Medical Institute, FL, USA.

Aftab R. Awan
University of Science, Arts and Technology, Montserrat, British West Indies and The University of Health and Humanities, Virgin Islands, UK and The Einstein Medical Institute, FL, USA.

George P. Einstein
University of Science, Arts and Technology, Montserrat, British West Indies and The University of Health and Humanities, Virgin Islands, UK and The Einstein Medical Institute, FL, USA.

View Book:- https://stm.bookpi.org/ETDHR-V6/article/view/6417

Can the Obese Phenotype Occur Via Epigenetic Expression? | Chapter 04 | Emerging Trends in Disease and Health Research Vol. 6

 Obesity is caused by a long-term caloric imbalance in which energy intake exceeds energy expenditure over months or years. It is thought to be the result of intricate interactions between environmental and heritable factors, yet determining which specific metabolic factors or genes endure has proven difficult and incomplete. Despite the fact that common forms of obesity have a relatively high heritability, accounting for 40 to 70% of the obese population, the identification and conformation of definitive genetic or epigenetic obesogenic variants that, when activated, may contribute to a susceptibility to excess weight gain has proven difficult. Obesity, overweight problems, and their direct link to hypertension are on the rise in the United States, reaching alarming, if not epidemic, proportions across much of Western culture and society in recent history. Despite significant advances in nutrition knowledge and practise, pharmacotherapeutic management, and lifestyle modifications, nearly one-third of the US population is now overweight, and the cost of medical management of overweight and obese conditions and their commonly associated pathophysiologic sequelae is becoming burdensome to public health and the medical community. The goal of this study was to look at the hormonal and metabolic mechanisms that may have a role in the development of the obese body type. Obesity usually develops gradually over months to years in most humans, but it develops more quickly in most extensively studied genetic models of obesity, where it usually follows the expression of an autosomal recessive genetic characteristic on chromosome 5 in rodent models. Obesity in humans is usually attributed to a mix of poorly defined genetically related features and environmental influences, but it is highly linked to heritable familial lines.

Author(S) Details

Orien L. Tulp
University of Science, Arts and Technology, Montserrat, British West Indies and The University of Health and Humanities, Virgin Islands, UK and The Einstein Medical Institute, FL, USA.

Aftab R. Awan
University of Science, Arts and Technology, Montserrat, British West Indies and The University of Health and Humanities, Virgin Islands, UK and The Einstein Medical Institute, FL, USA.

Nasheria Lewis
University of Science, Arts and Technology, Montserrat, British West Indies.

George P. Einstein
University of Science, Arts and Technology, Montserrat, British West Indies and The University of Health and Humanities, Virgin Islands, UK and The Einstein Medical Institute, FL, USA.

View Book:- https://stm.bookpi.org/ETDHR-V6/article/view/6416

The Metabolic Effects of Aging, Phenotype and Carbohydrate Feeding on Caloric Efficiency and Adiposity in the LA/Ntul//-Cp Rat | Chapter 08 | Emerging Trends in Disease and Health Research Vol. 5

 The goal of this work was to see if the decreased responses to diet in the obese phenotype were connected with corresponding alterations in CE, which could be correlated with the increased adiposity associated with the (-cp) trait. Obesity develops at 5 to 6 weeks of age in the obese phenotype of the LA/Ntul/-cp (corpulent) specific pathogen-free rat strain. Female congenic lean and obese LA/Ntul/-cp (corpulent) rats were fed ad libitum standardised Purina diets for 4, 14, or 24 months, or the same diet plus a 16 percent (w/v) sucrose solution supplement from 12 weeks of age, and body weight, caloric intake, and caloric efficiency (CE) were measured at each age group. Body weights of lean animals remained consistent across all ages tested, whereas body weights of obese phenotypes were considerably higher than those of their lean littermates across all years studied. The sucrose supplement had no influence on ultimate body weights in the lean phenotypes at all years tested (p=n.s. ), but was linked with higher body weights in the obese phenotype at ages 4, 14, and 24 months (p=0.05). CE was calculated as the ratio of kcal/gram of body weight per day, which stayed essentially constant in lean animals across the age range, but CE was more efficient in the obese phenotype at all ages investigated and grew progressively more efficient with sugar supplement feeding as age increased. The results of this study show that CE is associated with greater efficiency of energy utilisation and/or energy conservation in the obese phenotype of this strain than in the lean phenotype, and that the metabolic impact of added sucrose was associated with an additive effect on the CE of weight gain and adiposity in the obese. It was concluded that the -cp trait's autosomal recessive nature was associated with a greater economy of caloric efficiency and marked adiposity, which was exacerbated by ageing and compounded by the addition of a sucrose supplement, but was independent of derangements in appetite dysregulation per se.

Author(S) Details

Orien L. Tulp
University of Science Arts and Technology, Montserrat, British West Indies, USA.

View Book:- https://stm.bookpi.org/ETDHR-V5/article/view/6146