Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.4.1.2 (acetyl-CoA carboxylase)
 2,876 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Malonyl-CoA functions as a mediator in the hypothalamic sensing of energy balance and regulates the neural physiology that governs feeding behavior and energy expenditure. The central administration of C75, a potent inhibitor of the fatty acid synthase (FAS), increases malonyl-CoA concentration in the hypothalamus and suppresses food intake while activating fatty acid oxidation in skeletal muscle. Closely correlated with the increase in muscle fatty acid oxidation is the phosphorylation/inactivation of acetyl-CoA carboxylase, which leads to reduced malonyl-CoA concentration. Lowering muscle malonyl-CoA, a potent inhibitor of carnitine/palmitoyl-CoA transferase 1 (CPT1), releases CPT1 from inhibitory constraint, facilitating the entry of fatty acids into mitochondria for beta oxidation. Also correlated with these events are C75-induced increases in the expression of skeletal muscle peroxisome proliferator-activated receptor alpha (PPARalpha), a transcriptional activator of fatty acid oxidizing enzymes, and uncoupling protein 3 (UCP3), a thermogenic mitochondrial uncoupling protein. Phentolamine, an alpha-adrenergic blocking agent, prevents the C75-induced increases of skeletal muscle UCP3 and whole body fatty acid oxidation and C75-induced decrease of skeletal muscle malonyl-CoA. Thus, the sympathetic nervous system is implicated in the transmission of the "malonyl-CoA signal" from brain to skeletal muscle. Consistent with the up-regulation of UCP3 and PPARalpha is the concomitant increase in the expression of PGC1alpha, transcriptional coactivator of the UCP3 and PPARalpha-activated genes. These findings clarify the mechanism by which the hypothalamic malonyl-CoA signal is communicated to metabolic systems in skeletal muscle that regulate fatty acid oxidation and energy expenditure.
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PMID:Inhibition of hypothalamic fatty acid synthase triggers rapid activation of fatty acid oxidation in skeletal muscle. 1620 72

Loss of cardioprotection by adenosine in hearts stressed by transient ischemia may be due to its effects on glucose metabolism. In the absence of transient ischemia, adenosine inhibits glycolysis, whereas it accelerates glycolysis after transient ischemia. Inasmuch as 5'-AMP-activated protein kinase (AMPK) is implicated as a regulator of glucose and fatty acid utilization, this study determined whether a differential alteration of AMPK activity contributes to acceleration of glycolysis by adenosine in hearts stressed by transient ischemia. Studies were performed in working rat hearts perfused aerobically under normal conditions or after transient ischemia (two 10-min periods of ischemia followed by 5 min of reperfusion). LV work was not affected by adenosine. AMPK phosphorylation was not affected by transient ischemia; however, phosphorylation and activity were increased nine- and threefold, respectively, by adenosine in stressed hearts. Phosphorylation of acetyl-CoA carboxylase and rates of palmitate oxidation were unaltered. Glycolysis and calculated proton production were increased 1.8- and 1.7-fold, respectively, in hearts with elevated AMPK activity. Elevated AMPK activity was associated with inhibition of glycogen synthesis and unchanged rates of glucose uptake and glycogenolysis. Phentolamine, an alpha-adrenoceptor antagonist, which prevents adenosine-induced activation of glycolysis in stressed hearts, prevented AMPK phosphorylation. These data demonstrate that adenosine-induced activation of AMPK after transient ischemia is not sufficient to alter palmitate oxidation or glucose uptake. Rather, activation of AMPK alters partitioning of glucose away from glycogen synthesis; the increase in glycolysis may in part contribute to loss of adenosine-induced cardioprotection in hearts subjected to transient ischemia.
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PMID:Effects of adenosine on myocardial glucose and palmitate metabolism after transient ischemia: role of 5'-AMP-activated protein kinase. 1664 81