We previously reported that inhibition of epidermal growth factor receptor tyrosine kinase activity attenuates renal arteriolar contractile responses to angiotensin II. We performed the present experiments to determine if epidermal growth factor receptor tyrosine kinase activity contributes to the afferent arteriolar intracellular [Ca2+] response to angiotensin II. Afferent arterioles were diss...

OBJECTIVE To test the efficacy of tyrosine supplementation, as an adjunct to dietary treatment, on neuropsychological test performance in individuals with phenylketonuria. DESIGN A randomised controlled trial of tyrosine supplementation using a double blind crossover procedure with three four week phases. SETTING The Hospital for Sick Children, Toronto. PARTICIPANTS 21 individuals with ph...

The title compound, C(11)H(11)Br(2)NO(4)·0.5H(2)O, was prepared by an electrophilic bromination of N-acetyl-l-tyrosine in acetonitrile at room temperature. The two independent mol-ecules do not differ substanti-ally and a mol-ecule of water completes the asymmetric unit. The synthesis of the title compound does not modify the stereochemical center, as shown by the absolute configuration found i...

L-phenylalanine (Phe), an essential amino acid, is necessary for the synthesis of proteins such as catecholamine and melanin, also precursor acid L-tyrosine (Tyr). In this paper, optimized structures Phe, were calculated by using semi-empirical models AM1, PM3 MNDO; Density Functional (DFT) at B3LYP Hartreefock methods (HF) with 6-311++G (d,p) level. The energies geometric parameters Kaempferol...

In Bomirski Ab amelanotic hamster melanoma cells, L-tyrosine and/or L-dopa induce increases in tyrosinase activity as well as synthesis of melanosomes and melanin. L-tyrosine also modifies melanocyte-stimulating hormone (MSH) binding. In this paper we show that in the Bomirski amelanotic melanoma system MSH and agents that raise intracellular cyclic AMP induce dendrite formation, inhibit cell g...

We report the evolution of an RNA aptamer to change its binding specificity. RNA aptamers that bind the free amino acid tyrosine were in vitro selected from a degenerate pool derived from a previously selected dopamine aptamer. Three independent sequences bind tyrosine in solution, the winner of the selection binding with a dissociation constant of 35 microM. Competitive affinity chromatography...

The formation of angiotonin from the serum protein fraction art-globulin and renin (1, 2) as well as its inactivation by proteolytic enzymes suggests that this pressor substance contains peptide linkages. Preliminary studies and interpretations (3) of the action of crystalline proteolytic enzymes led to the conclusion that angiotonin contains groupings of which the simplest representation is af...