Immunohistochemical identification and quantification of brown adipocytes in human adipose tissue

الملخص EN

Background: Obesity is a worldwide challenge and is closely connected to many metabolic diseases.

Two types of adipose tissue, white adipose tissue (WAT) and brown adipose tissue (BAT) have been identified.

White fat cells store chemical energy, brown adipocytes defend against hypothermia, obesity and diabetes.

Objective: To localize and quantify brown adipocytes in human subcutaneous (S) and visceral (V) adipose tissue by histology and immunohistochemistry.

Type of the study: A cross –sectional study.

Methods: Adipose tissue was obtained from histopathology specimens taken from ten patients, of different age, sex and body mass index (BMI), undergoing surgery for different pathologies.

Immunohistochemistry for detection of UCP (Uncoupling Protein) in S and V adipose tissue depots was performed, and percentage of the positive pixels for UCP color intensity was measured and statistical analysis performed.data was expressed as mean ± standard deviation (SD) and analyzed using student t-test to compare values Results: Brown adipocytes with typicalmultivesicular appearance were detected as clusters of cells among white fat in both S and V adipose tissue.

The percentage of the positive pixels for UCP color intensity of brown adipocytes was significantly (P < 0.001 and P < 0.05) higher in S than in V adipose tissue, significantly higher levels (P < 0.05) when BMI was 30 or more, and non-significant higher levels (P > 0.05) in females than males.

Conclusion: Brown a dipocytes are more abundant in S than V adipose tissue, and have a positive correlation to BMI.