– by Bennetzen, M. F. (2011).
The study aimed to establish whether 10% weight loss would affect components of the ECS (Endocannabinoid System) in AT (adipose tissue) in humans and to establish whether hyperactivity of the ECS in adipose tissue is present in the obese state.
The obese study participants underwent a 12 weeks diet regimen resulting in 10-12% weight loss. The weight loss was achieved by a very low-calorie diet (NUPO) including 200 grams of fruit and vegetables daily and weekly motivation sessions with a dietician. All study participants underwent fasting blood samples and AT biopsies from the abdomen and gluteal region, the obese subjects both before and after weight loss. Setting and participants: A total of 21 healthy obese individuals (10 men/11 women, age 39.5 ± 1.6 years, body mass index (BMI): 37.5 ± 0.8 kg m(-2)) and 21 age- and gender-matched lean subjects (BMI: 23.8 ± 0.4 kg m(-2)) were studied. Main outcome measures: The activity of ECS in AT was determined by measuring arachidonoyl glycerol (2-AG) and N-arachidonoylethanolamine/anandamide in AT by mass spectrometry and gene expressions of enzymes and receptors involved in the ECS.
The EC, 2-AG was reduced in obese individuals in the gluteal AT depot (P<0.01). Moreover, 2-AG increased in both depots in the obese subjects following weight loss (P<0.05). The gene expression of the CB1 was either not affected by the obese state (in the gluteal AT depot) or reduced (in the abdominal depot, P<0.05) and significantly affected by weight loss. The expression of the degrading enzymes FAAH, FAAH2, MGL, and MGL2 was differently affected by obesity, AT depot, and weight loss.
We found reduced levels of 2-AG in subcutaneous AT in obesity, which increased after weight loss. In abdominal AT, the low CB1 expression was normalized after weight loss, whereas in gluteal AT the CB1 expression was reduced after weight loss. These findings support the concept of a dysregulated ECS in AT in association with obesity. Thus, both one of the important endogenous ligands, 2-AG, and the main EC receptor were down-regulated in the obese state, indicating that simple obesity is not associated with ECS hyperactivity in subcutaneous AT.
*The endocannabinoid system (ECS) is one of the signaling systems that control feeding behavior. The ECS is implicated in many functions, such as pain, memory, addiction, inflammation, and feeding, and could be considered a stress recovery system. It also seems to integrate nutrient intake, metabolism, and storage maintaining homeostatic balance. The ECS is a recently discovered system, and research indicates hyperactivity in obesity. The aim of this thesis is to elaborate on the relationships of this widespread system and its elements in adipose tissue in obesity.
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