title: A clinical approach to brown adipose tissue in the para-aortic area of the human thorax.
abstract: BACKGROUND
  Human thoracic brown adipose tissue (BAT), composed of several subdivisions, is a well-known target organ of many clinical studies; however, the functional contribution of each part of human thoracic BAT remains unknown. The present study analyzed the significance of each part of human thoracic BAT in the association between regional distribution, cellularity, and factors involved in the functional regulation of thoracic BAT.
  
  
  METHODS
  We analyzed 1550 healthy adults who underwent medical check-ups by positron-emission tomography and computed tomography (PET-CT) imaging, 8 cadavers, and 78 autopsy cases in an observational study. We first characterized the difference between the mediastinum and the supraclavicular areas using counts of BAT detection and conditions based on PET-CT outcomes. The measurable important area was then subjected to systematic anatomical and immunohistochemical analyses using anti-uncoupling protein 1 (UCP1) antibody to characterize the cellularity in association with age and sex.
  
  
  RESULTS
  In PET-CT scanning, the main site of thoracic BAT was the mediastinum rather than the supraclavicular area (P < 0.05). Systemic macroanatomy revealed that the thumb-sized BAT in the posterior mediastinal descending para-aortic area (paBAT) had feeding vessels from the posterior intercostal arteries and veins and sympathetic/parasympathetic innervation from trunks of the sympathetic and vagus nerves, respectively. Immunohistochemical analysis indicated that the paBAT exhibited immunoreactivity for tyrosine hydroxylase and vesicular acetylcholine transporter located in the pericellular nervous fibers and intracellular UCP1. The brown adipose cells of paBAT showed age-dependent decreases in UCP1 expression (P < 0.05), accompanied by a significant increase in vacuole formation, indicating fat accumulation (P < 0.05), from 10 to 37 years of age (P < 0.01).
  
  
  CONCLUSIONS
  paBAT may be one of the essential sites for clinical application in BAT study because of its visible anatomy with feeding vessels and sympathetic/parasympathetic innervation functionally affected by outer condition and senescence.
authors: Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan; Department of Molecular Anatomy, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Huixing
authors: H
authors: Wei
authors: Department of Molecular Anatomy, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Seiichi
authors: S
authors: Chiba
authors: Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan; Department of Molecular Anatomy, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Chinatsu
authors: C
authors: Moriwaki
authors: Department of Molecular Anatomy, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Hirokazu
authors: H
authors: Kitamura
authors: Department of Molecular Anatomy, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Keisuke
authors: K
authors: Ina
authors: Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan; Department of Molecular Anatomy, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Taishi
authors: T
authors: Aosa
authors: Oita Diagnostic Imaging Center of Shonin Hospital, 9 Shoningahama, Bepu, Oita, Japan.
authors: Kenichiro
authors: K
authors: Tomonari
authors: Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Koro
authors: K
authors: Gotoh
authors: Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Takayuki
authors: T
authors: Masaki
authors: Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Isao
authors: I
authors: Katsuragi
authors: Noguchi Thyroid Clinic and Hospital Foundation, 7-52 Aoyama, Bepu, Oita, Japan.
authors: Hitoshi
authors: H
authors: Noguchi
authors: Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Tetsuya
authors: T
authors: Kakuma
authors: Faculty of Medicine School of Nursing, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Kazuyuki
authors: K
authors: Hamaguchi
authors: Faculty of Medicine School of Nursing, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Tatsuo
authors: T
authors: Shimada
authors: Department of Molecular Anatomy, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Yoshihisa
authors: Y
authors: Fujikura
authors: Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama, Yufu, Oita, Japan.
authors: Hirotaka
authors: H
authors: Shibata
mesh_terms: D002001:Adipose Tissue, Brown / Q000166:cytology / Q000000981:diagnostic imaging*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D002102:Cadaver; D002648:Child; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007473:Ion Channels / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D024101:Mitochondrial Proteins / Q000096:biosynthesis; D010220:Para-Aortic Bodies / Q000166:cytology / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D013902:Radiography, Thoracic; D013909:Thorax / Q000166:cytology / Q000378:metabolism*; D000071256:Uncoupling Protein 1; D014617:Vacuoles / Q000378:metabolism
chemical_list: D007473:Ion Channels; D024101:Mitochondrial Proteins; C000604371:UCP1 protein, human; D000071256:Uncoupling Protein 1; D019788:Fluorodeoxyglucose F18