Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

[14C]Malonyl-CoA bound to intact mitochondria isolated from rat liver and heart in a manner consistent with the presence of two independent classes of binding sites in each tissue. The binding characteristics for mitochondria obtained from fed male rats were: for heart, KD(1) = 11-18nM, KD(2) = 30 microM, N1 = 7pmol/mg of protein, N2 = approx. 660pmol/mg of protein; for liver, KD(1) = 0.1 microM, KD(2) = 5.6 microM, N1 = 11pmol/mg of protein, N2 = 165pmol/mg of protein. In the presence of 40 microM-palmitoyl-CoA the characteristics of binding at the high-affinity sites were changed, so that for heart KD(1) = 0.26 microM, with no change in N1 and for liver KD(1) = approx. 2 microM, with N1 increased to approx. 40pmol/mg of protein. Differences between the two tissues in tightness of malonyl-CoA binding at the high-affinity sites explains the considerably greater sensitivity of heart CPT1 (overt form of carnitine palmitoyltransferase) to inhibition by malonyl-CoA [Saggerson & Carpenter, (1981) FEBS Lett. 129, 229-232; McGarry, Mills, Long & Foster (1983) Biochem. J. 214, 21-28]. Starvation (24h) did not change the characteristics of [14C]malonyl-CoA binding to liver mitochondria and did not alter the I50 (concentration giving 50% inhibition) for displacement of [14C]malonyl-CoA by palmitoyl-CoA. Therefore the decreased sensitivity of liver CPT1 to inhibition by malonyl-CoA in starvation [Saggerson & Carpenter (1981) FEBS Lett. 129, 225-228; Bremer (1981) Biochim. Biophys. Acta 665, 628-631] is not explained by differences in malonyl-CoA binding. Percentage occupancy of the high-affinity sites in heart mitochondria by malonyl-CoA correlated closely with percentage inhibition of CPT1 measured under similar conditions. This finding supports the proposal that the high-affinity binding sites are the functional sites mediating inhibition of CPT1 by malonyl-CoA. Similar experiments with liver mitochondria also suggested that the occupancy of high-affinity sites by malonyl-CoA regulates CPT1 activity. 5,5'-Dithiobis-(2-nitrobenzoic acid), which decreased the sensitivity of heart or liver CPT1 to inhibition by malonyl-CoA [Saggerson & Carpenter (1982) FEBS Lett. 137, 124-128], also decreased [14C]malonyl-CoA binding to the high-affinity sites of heart mitochondria. N1 values for [14C]malonyl-CoA binding to high-affinity sites in liver mitochondria were determined in various physiological states which encompassed a 7-fold range of CPT1 maximal activity (fed, starved, pregnant, hypothyroid, foetal). The N1 value did not change in these states.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Binding of malonyl-CoA to isolated mitochondria. Evidence for high- and low-affinity sites in liver and heart and relationship to inhibition of carnitine palmitoyltransferase activity. 648 67

Intestinal atrophy was induced in rats by infusion of 5% dextrose for 7 days with only oral water allowed. Compared with control animals fed standard rat chow (Purina Mills, St. Louis), the starved animals lost 30.5% of their initial body weight, 34.7% mucosal wet weight, 68.3% mucosal nitrogen content, 36.7% mucosal thickness, and 38.6% villous height and had variable losses of mucosal disaccharidase activities. Three groups of depleted rats were then refed with different regimens. One group was refed with standard Purina rodent chow (n = 15); a second group with a standard total parenteral nutrition (TPN) solution containing 16% glucose, 2.8% fat, and 4.25% standard amino acids (Travasol 8.5%, Baxter Healthcare Corporation, Deerfield, IL) (n = 15); and the third group with a TPN solution of 16% glucose, 2.8% fat, 2.75% standard amino acids, and 1.5% glutamine (n = 15). After 7 days of refeeding, rats were killed to determine the degree of intestinal recovery. Animals refed with standard TPN solution showed no significant recovery of intestinal mucosal weight, mucosal nitrogen content, villous height, mucosal thickness, or mucosal disaccharidase activities. Animals refed with glutamine-supplemented TPN solution demonstrated significant recovery of all parameters but not back to normal. Oral rodent chow completely restored intestinal anatomy and function. The addition of glutamine to TPN solutions significantly improved recovery of the intestine from starvation atrophy, and additional efforts to make it commercially available are indicated. This study again confirms the preferable use of a regular oral diet when clinically feasible and safe.
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PMID:Effect of glutamine-supplemented total parenteral nutrition on recovery of the small intestine after starvation atrophy. 845 20