Adipoz doku ve enerji metabolizması üzerine etkileri

Abstract

Two types of adipose tissue with different functions are found in humans, namely white adipose tissue and brown adipose tissue. White adipose tissue is present in large quantities in the body and it is considered an endocrine organ where excess energy is stored and it contributes to energy homeostasis. Brown adipose tissue provides thermoregulation especially in mammals and newborns. Uncoupling protein is the determinant protein of brown adipose tissue and it makes it possible for energy to be released as heat. Brown adipose tissue is located in the cervical, supraclavicular, axillary, paravertebral, mediastinal and upper abdominal regions in adults. White adipose tissue is stored in two main locations in the body, namely visceral white adipose tissue and subcutaneous white adipose tissue. Brown (beige) adipocytes may develop within white adipose tissue due to numerous environmental factors such as hormonal interactions, chronic cold exposure and exercise. Adipose tissue play a role in energy expenditure through various hormonal mechanisms. Brown adipose tissue is also present in adult humans and high amounts of it is linked to low body weight. Adipose tissue mitochondrial dysfunction is responsible for developing obesity. Activation of the sympathetic nervous system in reaction to cold exposure and food intake causes brown adipose tissue to be stimulated. This brown adipose tissue based reaction is defined as cold-induced thermogenesis and thermic effect of food and it increases total energy expenditure. This compilation examines properties of adipose tissue and their effects on energy expenditure.

Obezite Yönetiminde Adipoz Doku Kahverengileşmesi

“…Beyaz adipositlerdeki mitokondriya, kahverengi adipositlere göre zayıf ve değişken miktardadır, bu yüzden KAD'nun oksijen ihtiyacı BAD'dan daha fazladır (10). BAD, vücutta visseral beyaz yağ dokusu ve subkutan beyaz yağ dokusu olmak üzere iki ana bölgede depolanır (3,11). Çevresinde büyük bir lipid damlası yer alan beyaz adipositlerden oluşur.…”

“…Apelin kan basıncı dengesinde görev alırken, leptin enerji homeostazının düzenlenmesi görev almaktadır. Böylece adipositokinlerin enerji dengesi kontrolündeki bu görevleri, obezitenin gelişiminde aktif bir rol almaktadır (10,11). Kahverengi adipositler, multiloküler lipid damlacıkları ve "uncoupling protein 1" (UCP1, ayrıca termojenin) adı verilen benzersiz bir protein içeren bol miktarda mitokondri ile (15,25,26).…”