White adipocytes

Schluter, A. et al.. The chlorophyll-derived metabolite phytanic acid induces white adipocyte differentiation, Int. J. Obes., 26, 1277, 2002. 

Mechanically, the bones that constitute the skeleton provide protection, support and a framework of levers which enable attached muscles to develop the forces that make locomotion possible. Within cavities in the long bones of the limbs is the bone marrow, where erythrocytes (red cells) and immune cells (white cells) are produced for the blood and lymph. Adipocytes are also present in the bone marrow indeed they oumumber the other cells (see Chapters 7 and 17). 

Picard, F., Kurtev, M., Chung, N., Topark-Ngarm, A., Senawong, T, Machado De Oliveira, R., Leid, M McBurney, M.W. and Guarente, L. (2004) Sirtl promotes fat mobilization in white adipocytes by repressing PPAR-gamma. Nature, 429, 771-776. 

Scanning electron micrograph of white adipocytes from rat adipose tissue (600 X). (Courtesy of Dr. A. Angel, University of Manitoba, and Dr. M. J. Hollenberg of the University of Toronto.)... 

We have observed that suppression of elevated FFA levels is a very rapid (less than 12 hour) response to treatment of insulin-resistant rats with PPARy agonists (T. Doebber, unpublished data). Since PPARy agonists are known to promote adipose tissue uptake and storage of fatty acids, it is plausible that this effect constitutes a major mechanism of insulin sensitization, whereby elevated FFAs—a known cause of hepatic and muscle insulin resistance—can be alleviated. An additional effect of in vivo PPARy activation, shown to occur in rats, was an increase in the number of small white adipocytes, along with a relative shift in the size of visceral (decreased) versus subcutaneous (increased) adipose depots (73). This has important implications because visceral adiposity and larger fat cells are both associated with insulin resistance. 

Okuno, A., Tamamoto, H., Tobe, K., Ueki, K., Mori, Y., Iwamoto, K., Umesono, K., Akanuma, Y., Fujiwara, T., Horikoshi, H., Yazaki, Y., and Kadowaki, T. (1998). Troglitazone Increases the Number of Small Adipocytes Without the Changes of White Adipose Tissue Mass in Obese Zucker Rats./. Clin. Invest. 101, 1354-1361. 

MacEiougald, O. A., Hwang, C.-S., Fan, H., and Lane, M- D. (1995). Regulated expression of the obese gene product (leptin) in white adipose tissue and 3T3-L1 adipocytes. PriTc. Natl- Acad. Sci. U.S.A. 92,9034-9037-... 

Increased expression of ob gene in adipocytes, and increased secretion of leptin by white adipose tissue into the bloodstream. 

The expression and function of human P3-ARs were investigated in subcutaneous white adipocytes of young healthy women. In these cells, P3-AR mRNAs represent 20% of total P-AR transcripts and less than half of Pi-AR transcripts (72). Rabbit perirenal adipose tissue expressed all three P-AR mRNAs (71). 

Tavernier G, Barbe P, Galitzky J, et al. Expression of p3-adrenoceptors with low lipolytic action in human subcutaneous white adipocytes. J Lipid Res 1996 37 87-97. 

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