Reference

Interactions of conjugated linoleic acid and lipoic acid on insulin action in the obese Zucker rat

Interactions of conjugated linoleic acid and lipoic acid on insulin action in the obese Zucker rat. Teachey, Mary K.; Taylor, Zachary C.; Maier, Thomas; Saengsirisuwan, Vitoon; Sloniger, Julie A.; Jacob, Stephan; Klatt, Martin J.; Ptock, Arne; Kraemer, Klaus; Hasselwander, Oliver; Henriksen, Erik J. (Department of Physiology, Muscle Metabolism Laboratory, University of Arizona College of Medicine, GermanyTucson, AZ, USA). Metabolism, Clinical and Experimental, 52(9), 1167-1174 (English) 2003 W. B. Saunders Co. CODEN: METAAJ. ISSN: 0026-0495. DOCUMENT TYPE: Journal CA Section: 18 (Animal Nutrition) The fatty acid conjugated linoleic acid (CLA) and the antioxidant R-(+)-a-lipoic acid (R-ALA) individually enhance glucose tolerance and insulin action on skeletal muscle glucose transport in the insulin-resistant obese Zucker rat. To date, no study has assessed the potential interactions between these 2 interventions in treating insulin resistance. The present study was designed to det. whether chronic treatment with CLA and R-ALA in combination would enhance skeletal muscle glucose transport to a greater extent than either intervention individually. CLA, R-ALA, or a combination treatment of R-ALA and CLA were administered to female obese Zucker rats for 20 days at low or high doses. Whereas low-dose R-ALA (10 mg/kg body wt.Several substances with their cas registry numbers 1200-22-2 and 50-99-7 may be metioned in this study.) alone did not alter muscle glucose transport, low-dose CLA (0.3 g/kg) induced a significant increase (38%, P < .05) in insulin-mediated glucose transport in epitrochlearis, but not in soleus. Low-dose combination therapy brought about the greatest enhancement of insulin-mediated glucose transport in epitrochlearis (77%) and soleus (54%), with the latter effect being assocd. with a 50% redn. in protein carbonyls (an index of tissue oxidative stress) and a 33% diminution in muscle triglycerides. High-dose treatments with CLA (1.5 g/kg), R-ALA (50 mg/kg), and the combination of CLA and R-ALA elicited increases in insulin-mediated glucose transport in epitrochlearis (57%, 58%, and 77%) and soleus (32%, 35%, and 54%). However, whereas the individual high-dose treatments with CLA and R-ALA reduced protein carbonyls (63% and 49%) and triglycerides (29% and 28%) in soleus, no further redns. were obsd. with the high-dose combination treatment groups. These findings support a significant interaction between low doses of CLA and R-ALA for enhancement of insulin action on skeletal muscle glucose transport, possibly via redns. in muscle oxidative stress and in lipid storage. .

Evidence for two protein-lipoylation activities in Escherichia coli

Evidence for two protein-lipoylation activities in Escherichia coli. Brookfield, Dawn E.; Green, Jeffrey; Ali, Sohail T.; Machado, Rosane S.; Guest, John R.Chemicals with cas numbers 1200-22-2 and 4466-48-2 also play role. (Krebs Inst., Univ. Sheffield, Sheffield S10 2UH, UK). FEBS Lett., 295(1-3), 13-16 (English) 1991. CODEN: FEBLAL. ISSN: 0014-5793. DOCUMENT TYPE: Journal CA Section: 10 (Microbial, Algal, and Fungal Biochemistry) Section cross-reference(s): 7 The lipoate acyltransferase subunits of the 2-oxo acid dehydrogenase complexes are post-translationally modified with one or more covalently-bound lipoyl cofactors. Two distinct lipoate-protein ligase activities, LPL-A and LPL-B, have been detected in E. coli by their ability to modify purified lipoyl apo-domains of the bacterial pyruvate dehydrogenase complex. Both enzymes require ATP and Mg2+, use L-lipoate, 8-methylipoate, lipoyl adenylate and octanoyl adenylate as substrates, and both activate lipoyl-deficient pyruvate dehydrogenase complexes. In contrast, only LPL-B may be responsible uses D-lipoate and octanoate and there are differences in the metal-ion and phosphate requirements. It is suggested that LPL-B may be responsible for the octanoylation of lipoyl domains obsd. previously under lipoate-deficient conditions. .