The Chemistry Of Adrenochrome And Related Compounds

Heacock, R. A.

doi:10.1021/cr50026a001

Cited by 167 publications

(60 citation statements)

References 96 publications

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“…Spectrophotometric analysis (11) revealed that after as much as 120 min of incubation of thymocytes with 10 ,uM epinephrine, concentrations of adrenochrome were below the limit of detectability (10 nM).…”

Section: Methodsmentioning

confidence: 99%

Direct and Synergistic Interactions of 3,5,3′-Triiodothyronine and the Adrenergic System in Stimulating Sugar Transport by Rat Thymocytes

Segal¹,

Ingbar²

1980

J. Clin. Invest.

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A B S T R A C T Isolated rat thymocytes were preincubated with various catecholamines, alone and together with 3,5,3'-triiodothyronine (T3), and the accumulation of the glucose analogues, 2-deoxy-D-glucose (2-DG) and 3-0-methylglucose (3-0-MG), was then measured. Epinephrine induced a time-and dose-dependent increase in the 15-min accumulation of 2-DG; at a concentration of 100 ,uM epinephrine, the effect was evident after a preincubation period of only 5 min. The lowest concentration of epinephrine at which a significant effect was evident was 1 uM. Epinephrine also produced a dose-dependent increase in the accumulation of 3-0-MG, and the lowest concentration at which a significant effect was evident was again 1 uM. Isoproterenol, a f-adrenergic agonist, like epinephrine, increased the accumulation of 2-DG, whereas the aagonist, phenylephrine, had no effect. The response to epinephrine was inhibited by the ,8-antagonist, alprenolol, but the a-antagonist, phentolamine, had no effect. As previously demonstrated, T3 increased 2-DG accumulation, and like epinephrine, its effect was blocked by alprenolol. Neither T3 (0.1 nM) nor epinephrine (0.1 uM) had any effect when acting alone, but when added together at these concentrations, they significantly increased the accumulation of both 2-DG and 3-0-MG. Neither T3 with isoproterenol nor T3 with phenylephrine produced a comparable synergistic effect. But T3 (0.1 nM) acting with isoproterenol (0.1 ,M) and phenylephrine (0.1 ,\M) together, synergistically increased 2-DG accumulation. In addition, the a-antagonist, phentolamine, which alone had no effect, inhibited the synergistic effect induced by T3 and epinephrine. The effects of epinephrine and T3 alone, as well as their combined synergistic effect on 2-DG accumulation, were not blocked by the inhibitor of protein synthesis, puromycin.Received for publication 5 September 1979 and in revised form 5 November 1979. 958 From these results we conclude the following: (a) the stimulatory effect of the catecholamines on the accumulation of 2-DG and 3-0-MG reflects an action at the 13-receptor; (b) the synergistic interaction between T3 and epinephrine requires the participation of both 18-and a-adrenergic components; (c) T3 and epinephrine act on 2-DG and 3-0-MG accumulation through a common mechanism or inter-related mechanisms, probably mediated at the 3-adrenergic site; and (d) these effects of T3 and epinephrine, alone and together, are independent of new protein synthesis. These results suggest that, with respect to the response we are describing, T3 and epinephrine do not act on nuclear mechanisms;, but may act instead at the level of the plasma membrane.

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Section: Methodsmentioning

confidence: 99%

Direct and Synergistic Interactions of 3,5,3′-Triiodothyronine and the Adrenergic System in Stimulating Sugar Transport by Rat Thymocytes

Segal¹,

Ingbar²

1980

J. Clin. Invest.

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“…From these experiments we postulate the following reaction Scheme 1 involving the intermediate complex of metal ions and DC, in close analogy with the copper and zinc-catalyzed conversion of aminochromes. 43,60 When the concentration of aluminum ions is rather high compared with the concentrations of iron and DC, competitive reactions of Al 3+ and Fe 3+ with DOPA and its derivative exist. The rate of DOPA oxidation catalyzed by Fe 3+ in the presence of a large quantity of Al 3+ is lower than the rate in the presence of appropriate Al 3+ but approximately the same as the rate in the absence of Al 3+ in the early reaction process.…”

Section: +mentioning

confidence: 99%

Aluminum Facilitation of the Iron-Mediated Oxidation of DOPA to Melanin

2004

ANAL. SCI.

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Aluminum, a trivalent cation unable to undergo redox reactions, is shown to faciliate iron-initiated DOPA oxidation in the melanin pathway under acidic condition of pH 5.5, which is a favored medium for aluminum facilitation of iron-induced lipid peroxidation. In the process of oxidation of DOPA to melanin in the presence of the metal ions, Fe 3+ and H2O2 oxidize DOPA to dopachrome (DC), then Al 3+ catalyzes the conversion of DC to 5,6-dihydroxyindole (DHI) and finally Fe 3+ oxidizes DHI to indole-5,6-quinone (IQ), which polymerizes immediately to melanochrome and melanin. The reactions involve the intermediate complexes of metal ions and DOPA or its derivative. The present results indicate that aluminum can enhance the oxidative stress on iron-mediated DOPA oxidation in melanin pathway under acidic condition through the cooperation of iron and aluminum ions.

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“…Furthermore, the yield of adrenochrome increases if ADR semi-quinone reacts with O 2 to form O 2 • - (Costa et al, 2007). This seems to be a general phenomenon of aminochromes, since it occurs also with the other catecholamines (Heacock, 1959, Bindoli et al, 1992.…”

Section: Another Pathway To Degrade Catecholaminesmentioning

confidence: 98%

“…When the enzymes dealing with the catabolism of catecholamines are unable to cope efficiently, their levels rise and catecholamines can undergo oxidation. The oxidation rate is faster under enzymatic or metal catalysis (Heacock, 1959, Bindoli et al, 1992, Foppoli et al, 1997, in the presence of the superoxide anion (O 2 • -) or high pH (West, 1947, Spencer et al, 1995, Costa et al, 2007. Although at physiological pH, the oxidation of catecholamines seems to occur very slowly, it has been found to occur in vivo namely in the septic shock (Macarthur et al, 2000).…”

Section: Another Pathway To Degrade Catecholaminesmentioning

confidence: 99%

“…In summary, the oxidation of catecholamines occurs through two-stages whereby a total of four electrons is removed and an indole is formed by cyclization (Costa et al, 2011). Adrenochrome is the most studied aminochrome due to its stability (Heacock, 1959, Rupp et al, 1994. When adrenochrome is formed and ADR still exists in solution, adrenochrome accelerates the oxidation process of the remaining ADR (Bindoli et al, 1999, Costa et al, 2007.…”

Section: Another Pathway To Degrade Catecholaminesmentioning

confidence: 99%

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