Neurotensin Receptor Implication in Cancer

Increasing evidence demonstrates that proNT and NTS1 are deregulated in several human cancers such as colon, pancreatic, prostate, and lung cancer, suggesting that NT may exert an autocrine activation of its own NTS1 receptor in cancer. Thus, the use of NT receptor antagonists to block the proliferative effect of NT on cancer cells is one of the promising prospects in cancer therapy. In this respect, it has been recently reported that SR 48692 could inhibit NT-stimulated growth of human colon,...

Pentose Phosphate Pathway History of

Australian National University, Canberra, Australia In this article the oxidative and non-oxidative segments of the pentose pathway (PP) of glucose metabolism are defined. The discovery in 1931-1935 by the German biochemist, Otto Warburg, of the oxidative division of the pathway and of the chemistry and role of a new pyridine nucleotide co-enzyme in its reactions is deliniated. The successful revelation of many of the reactants and enzymes of the non-oxidative PP was largely achieved by two...

Neurotensin Receptor Implication in Brain Functions

Neurotensin and Dopamine Interaction More than twenty years ago, it was observed that some behavioral and biochemical effects of centrally administered NT were similar to those exhibited by antipsycho-tic drugs, and that these drugs stimulated NT expression in brain regions where there are mesocorticolimbic and nigrostriatal DA neuronal projections. These observations led to the hypothesis that NT may act as an endogenous neuroleptic, and stimulated the research on NT-DA interactions. Moreover,...

P70 S6 Kinase

This family of enzymes phosphorylates a series of seryl residues in the C-terminus of S6. It was identified in the 1980s following early work showing that insulin, and a range of other stimuli, led to increased phosphorylation of S6. The p70 S6 kinases were some of the earliest insulin- and mitogen-stimulated kinases to be studied in any detail, largely because the relatively high abundance of S6 means that it appears as a major insulin-stimulated phosphoprotein. p70 S6 kinases are now believed...

Cps

FIGURE 4 Extrahepatic arginine synthesis. ASL, argininosuccinate lyase, ASS, argininosuccinate synthetase, CPS 1, carbamoyl phosphate synthetase 1, OTC, ornithine transcarbomylase, OAT, ornithine aminotransferase, P5C, pyrroline 5-carboxylate. but the very high arginase activity of the liver means that both dietary arginine and arginine synthesized within the liver are rapidly hydrolyzed and not available to the body. Thus the arginine required for the synthesis of protein, nitric oxide,...

Ornithine Cycle

Rutgers University, New Brunswick, New Jersey, USA The ornithine cycle, also known as the urea cycle and the Krebs-Henseleit cycle, is the pathway in mammalian liver that allows the detoxification and excretion of excess nitrogen as urea. Flux through the cycle is driven by the demand to remove excess ammonia derived from the degradation of amino acids that arise either from the diet or from endogenous proteolysis. In a healthy individual, consuming a typical western diet, flux through the...

Atrial Natriuretic Peptide

Atrial Natriuretic Peptide Anp

The first natriuretic peptide to be identified was atrial natriuretic peptide (ANP), which was originally called atrial natriuretic factor (ANF) because of its unknown structure. It was discovered by de Bold and co-workers in 1981. They found that intravenous infusion of atrial, but not ventricular, homogenates into rats caused a rapid and dramatic increase in renal sodium and water excretion that was accompanied by reduced blood pressure. Subsequently, a smooth muscle relaxing activity was...

Biological Function of Oxygenases

While oxidases and dehydrogenase are mainly involved in energy metabolism, namely, the generation of ATP, oxygenases play important roles in biosynthesis, transformation, and degradation of essential metabolites such as amino acids, lipids, sugars, porphyrins, vitamins, and hormones. They also play a crucial role in the metabolic disposal of foreign compounds such as drugs, insecticides, and carcinogens. Furthermore, they participate in the degradation of various natural and synthetic compounds...