AU - Jalali, M. AU - Nikravesh, MR AU - Fazel, AR TI - Histochemical study of the expression time and pattern of distribution of brown adipose tissue in Balb/c mouse PT - JOURNAL ARTICLE TA - QHMS JN - QHMS VO - 11 VI - 1 IP - 1 4099 - http://imtj.gmu.ac.ir/article-1-185-en.html 4100 - http://imtj.gmu.ac.ir/article-1-185-en.doc SO - QHMS 1 AB  - Background and Aim: During organogenesis two different type of adipose tissue developed which are different in morphology، vascularity and distribution. White adipose has very diffuse distribution but brown adipose has very restricted distribution. Human embryo has also this type of fat، but amount of brown adipose is decreased during the fetal period and after birth so that all type of fat change into white type in adult. In this investigation the pattern of brown adipose tissue in mouse embryo was studied Materials and Methods: In this exprimental study 20 Balb/c mice were used. Vaginal plug was recognized as day 0 of pregnancy. Embryos from day 10 to 18 and pops among 5th، 10th، 15th as well as adults were collected and fixed in Paraformaldehyde or FAA (formaline، alcohol، acetic acid)، serial frozen section and histochemical staining by using Nile blue sulphate and Sudan IV were carried out. Results: The first sign of brown adipose tissue was observed at day 14th of gestation around the scapula and after that it can be detected in other sites such as around the abdominal aorta from day of 16th and in hilus of the kidney and great vessels of the neck after day 17th of gestation، but the most amount of brown adipose were concentrated around the scapula. That at day 18th of gestation two symmetrical mass of brown fat are located between two scapula bones. These data also revealed that the composition of lipid in brown adipose tissue at day 16th of gestation، consist of 55% triglyceride in the form of neutral fat، and about 45% in the form of phospholipid and fatty acids but in new born animal from P1 to P15 there is a shift away from phospholipid and fatty acids to neutral fat. Conclusion:It seems that during fetal life some of the indifferent cells form a lobule of epitheloid cells through symmetrical mass and the fat elements are developed in the form of brown adipose tissue ,however it may changed to white adipose directly by fat storage. CP - IRAN IN - LG - eng PB - QHMS PG - 10 PT - Original YR - 2005