Showing papers in "Advances in Enzyme Regulation in 1963"

TL;DR: The data show that there is selectivity in both enzyme induction and inhibition which reveals operation of exact regulatory effects influencing carbohydrate enzyme activity and synthesis in the liver, and may be interpreted postulating that the Enzyme Forming Systems of the same carbohydrate enzymes in liver and kidney differ in their sensitivity to the enzyme synthesis-inducing effects of cortisone.

TL;DR: Ethionine inhibition experiments suggest that the hepatic glucose-6-phosphate dehydrogenase increase seen on refeeding and after fructose feeding probably represents de novo protein synthesis, and suggest that inhibition of lipogenesis results in a dimunition of glucose- 6- phosphate oxidation by way of the pentose pathway.

TL;DR: Pretreatment of rats with various polycyclic aromatic hydrocarbons or drugs markedly stimulates the activity of TPNH-dependent drug-metabolizing enzymes in liver microsomes, which accelerates the metabolism of naturally occurring compounds such as steroids and reduced TPN.

TL;DR: Evidence is provided that the administration of foreign compounds enhances the activity of the drug metabolizing enzymes through at least three different mechanisms: One evoked by anabolic steroids, another by polycyclic hydrocarbons, and a third by phenobarbital.

TL;DR: There is a progressive loss of the biochemical response to cortisone administration as manifested in failure of enzyme induction and nitrogen and glycogen deposition in hepatomas, and the host livers also showed decreased or absent sensitivity to Cortisone induction.

TL;DR: The distribution of aldolase A can be correlated with the prominence of the Embden-Meyerhof pathway for degradation of sugars, while a Aldolase B occurs in tissues with greater metabolic diversification.

TL;DR: Two ways in which factors regulating enzyme synthesis in adult or developing tissues may operate are exemplified and may influence the number of potential synthetic sites (RNA template units) or the speed of functioning of a constant number of these sites.

TL;DR: Of four enzymes studied in rat hepatomas, corticoids have been shown to affect their enzyme-forming systems minimally, variably or maximally, and steps are now being taken to understand the molecular changes present in the hepatoma cell which are responsible for the observed metabolic defects.

TL;DR: Alanine transaminase activity in liver can be increased or decreased from its normal level by various physiological conditions but the relative change in the activity of this enzyme does appear to reflect changes in metabolism associated with the growth inhibitory effect of cortisol on such tissues.

TL;DR: Immunochemical and isotopic analysis of the mechanism of adrenal control of the tyrosine-α-ketoglutarate transaminase activity of rat liver demonstrates that activity changes reflect changes in the rate of transaminases synthesis.

TL;DR: Treatment of rats with ethanol, ethionine, or carbon tetrachloride increases the incorporation by liver homogenates of 1-C14-palmitate into triglycerides and decreases the incorporation into phospholipids, and increased enzymic incorporation of a fatty acid into LDL may contribute to the development of a triglyceride fatty liver after these agents.

TL;DR: Predictions of the level of microsomal drug-metabolizing enzyme activity are best made from the amount of SSE in the hepatic parenchymal cell since hepatic glycogen levels can be changed (e.g. by epinephrine injections).

TL;DR: Evidence is cited in support of the thesis that the creatine-transamidinase control system has survival value for birds, and perhaps reptiles and amphibians.

TL;DR: Simultaneous observations of fluorescence changes in the kidney and liver of the anesthetized rat are here interpreted in terms of oxidations and reductions of intracellular pyridine nucleotide based upon the idea that the energy load in the kidneys drops in hypoxia while that of the liver is constant.

TL;DR: It would appear that the synthesis of new molecules of tryptophan pyrrolase from amino acids, both during development and in response to l-tryptophan, requires the simultaneous synthesis of RNA.

TL;DR: The results of the present study indicate that, at least under some pathologic circumstances, the tissue level of ATP may be an important determinant of enzymatic activity in the liver.

TL;DR: The increased deposition of TGL in the livers of rats exposed to cold or given narcotic doses of ethanol or morphine is dependent upon the integrity of both the sympathetic nervous system and the pituitary-adrenocortical system.

TL;DR: A heterogeneous, rapidly labeled ribonucleic acid fraction, ranging in size from 6 to more than 30 S, has been found in rat liver nuclei and it is found that the rapidly labeled nuclear RNA is broken down to 5′- and 3′-mononucleotides by rat liver nuclear extracts, but only to3′- nucleotide by cytoplasmic extracts.

TL;DR: Thyroxin injection on two consecutive days produces a marked decrease of the liver amine oxidase but a very slight decrease of catechol-O-methyltransferase, while 3,5-diiodothyronine acts as a non-competitive inhibitor.

TL;DR: Studies on the nature of inhibition demonstrated that CB-2511 resulted in a non-competitive inhibition of fructose-1,6-diphosphatase activity.