Lactate, Pyruvate and Acetate Interactions during in Vitro Lipogenesis in Bovine Adipose Tissue

Lipogenesis in adipose tissue from cattle

“…Prior and Jacobson (1979b) have shown that pyruvate and lactate are both decarboxylated before being converted to fatty acids by bovine adipose tissue. These observations of lactate and pyruvate metabolism by ruminant adipose tissues are difficult to reconcile with the commonly accepted explanation that low citrate cleavage pathway activity limits use of glucose for fatty acid synthesis in lipogenic tissues of ruminants.…”

“…This observation by Ingle et al (1973) (Prior and Jacobson, 1979a). Prior and Jacobson (1979b) found that pyruvate could be uti lized at greater rates than acetate in the absence of glucose in vitro by bovine adipose tissue; Prior and Jacobson (1979c) have reported greater rates of utilization of pyruvate than glucose for fatty acid synthesis by bovine adipose tissue.…”

“…Furthermore, both pyru vate and lactate are decarboxylated before being converted to fatty acids (Prior and Jacobson, 1979b). Heretofore, the in volvement of the citrate cleavage pathway for lactate con version to fatty acids in bovine adipose tissue has not been demonstrated.…”

“…The inability of ruminants to utilize glu cose for fatty acid synthesis has been attributed to the low activity of the citrate cleavage pathway (Ballard and Hanson, 1967a). Recent investigations have demonstrated that lactate is a fatty acid precursor in ovine (Prior, 1978) and in bovine adipose tissues (Whitehurst et al, 1978;Prior and Jacobson, 1979b) and have challenged the explanation that low citrate cleavage pathway activity results in poor utilization of glu cose for lipogenesis in ruminant tissues (Ballard and Hanson, 1967a). No studies of lactate utilization for lipogenesis in cattle at several stages of growth and development have been performed.…”

“…Prior (1978) reported that lactate was used for carcass lipid formation by sheep 40% to 70% as well as acetate depending upon the dietary energy intake. Prior and Jacobson (1979b) have shown that both pyruvate and lactate are decarboxylated during conversion to fatty acids by bovine adipose tissue. In the present study, both lactate and acetate were used at similar rates for fatty acid synthesis in subcutaneous, intermuscular and intramuscular adipose tissues of growing cattle, which further confirms observations by Whitehurst et al (1978).…”