AbstractThe effect of fish-meal supplementation or cimaterol administration on the composition, cellularity and metabolism of subcutaneous and perirenal adipose tissue was examined in young Friesian steers given grass silage. Animals (approx. 117 kg live weight) received either silage alone (group C; no. = 6) or supplemented with fish meal (150 g/kg silage dry matter; group FM; no. = 6) or cimaterol (0·06 mg/kg body weight per day) administered via osmotic minipumps (group CIM; no. = 6) for a period of 6 weeks. Samples of perirenal and subcutaneous adipose tissue obtained at slaughter were used for determination of tissue composition andin vitrorates of lipogenesis, lipolysis and substrate oxidation. FM animals showed significantly greater live-weight gains (0·61 kg/day) compared with C (0·21 kg/day,P< 0·001) while CIM animals had significantly lower rates of gain (0·04 kg/day,P< 0·05). This was considered to be related to increased heat loss from the β-agonist-treated animals as a result of very cold weather encountered during the experimental period. CIM administration reduced adipocyte size suggesting an increased number of cells per g tissue. Both lipolytic and lipogenic rates were reduced by cimaterol and there was some evidence that the response to insulin was diminished, at least with respect to substrate oxidation. FM increased lipogenesis from acetate and acetate oxidation rates in subcutaneous adipose tissue with similar trends in perirenal tissue. The results indicate that both fish-meal supplementation and cimaterol administration caused substantial changes in adipose tissue metabolism as determined usingin vitroprocedures, even though the magnitude and direction of the changes were not in strict accord with estimates of net fat accretion from relatedin vivostudies.
Autologous subcutaneous adipose tissue transplants improve adipose tissue metabolism and reduce insulin resistance and fatty liver in diet-induced obesity rats
