Changes in adipose tissue accumulation in Rasa Aragonesa breed lambs during growth and fattening

Abstract

AbstractChanges during growth and fattening in the number and size of adipocytes and in the activity of the lipogenic enzymes glycerol 3-phosphate dehydrogenase (G3PDH), fatty acid synthetase (FAS) and lipoprotein lipase (LPL) were studied in perirenal (PR) and subcutaneous (SO adipose depots of 28 male lambs of Rasa Aragonesa Spanish breed. Three groups of animals were slaughtered at: 32 (s.d. 6) (no. = 10), 89 (s.d. 8) (no. = 10) and 120 (s.d. 8) (no. = 8) days of age. A significant increase in the quantity of fat was observed as the age of the lambs increased (P< 0·001). Fat deposition was higher between 89 and 120 days of age. The number of adipocytes in the PR depot did not change but hypertrophy in this depot continued during the whole period studied (P< 0·001). In the SC depot a significant increase in adipocyte volume was only found between 89 and 120 days of age (P< 0·001). The increase in G3PDH activity (which estimates fatty acid esterification) and FAS activity (which estimates fatty acid synthesis) was greater in the final phase of the study. Besides, LPL enzyme activity (which estimates the uptake of plasma fatty acids) increased between 32 and 89 days of age in both depots and between 89 and 120 days in PR depot (P< 0·001).