Glycerolipid biosynthesis in rat adipose tissue. 7. Effect of age, site of adipose tissue and cell size.
Adipose glycerolipid formation was studied in relation to age, site of adipose tissue and cell size in developing rats. Glycerolipid formation was measured in vitro in the presence of [14C]glycerol 3-phosphate, palmitate, ATP, CoA and Mg2+ by using adipocyte homogenates derived from various age groups of animals. In the epididymis fat pads, glycerolipid formation was very low in 15-day-old rats, increased 5--6 fold in 30-day-old rats and reached maximal at 60 days of age. This rise in glycerolipid formation with age was related to increase in the adipocyte size. At latter ages, in spite of the increase in adipocyte size, glycerolipid formation declined. The decline in glycerolipid formation with age was also apparent in the perirenal and subcutaneous adipocytes. Adipocyte homogenates derived from various age groups of animals and form various fat depots formed phosphatidate, diacylglycerol and triacylglycerol as the major reaction products from [14C]glycerol 3-phosphate. The proportions of the various lipids formed changed significantly as a function of age of the animal. In addition, changes in the adipocyte size with age were determined. Adipose tissues from 15-day-old rats contained smaller adipocytes with a mean cell diameter around 30 micrometer. As the rats grew older, the presence of more larger adipocytes was detected in their fat depots. These studies suggest that adipose glycerolipid synthesis changes with age and anatomical location of the adipose organ independently of the adipocyte size.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism*; D000375:Aging; D000818:Animals; D003065:Coenzyme A / Q000378:metabolism; D004822:Epididymis; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000378:metabolism; D005994:Glycerophosphates / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D008297:Male; D010168:Palmitates / Q000378:metabolism; D010712:Phosphatidic Acids / Q000096:biosynthesis; D051381:Rats; D012867:Skin; D014280:Triglycerides / Q000096:biosynthesis
D005994:Glycerophosphates; D010168:Palmitates; D010712:Phosphatidic Acids; D014280:Triglycerides; D000255:Adenosine Triphosphate; D005992:Glycerol-3-Phosphate O-Acyltransferase; D008274:Magnesium; D003065:Coenzyme A