A rapid and simple radioassay for tyrosine hydroxylase activity

Nagatsu, Toshiharu; Levitt, Morton; Udenfriend, Sidney

doi:10.1016/0003-2697(64)90092-2

Cited by 574 publications

(197 citation statements)

References 3 publications

Supporting

Mentioning

193

Contrasting

Order By: Relevance

“…Tyrosine hydroxylase activity was measured in the 30,000 g supernatant fluid from a single pressed heart or in an aliquot of the homogenate of a pair of adrenal glands or two blood vessels by a modification of the radioisotope method of Nagatsu, Levitt & Udenfriend -(1964). Monoamine oxidase activity was measured in homogenized individual tissues by the radioisotope method of Wurtman & Axelrod (1963).…”

Section: Methodsmentioning

confidence: 99%

Resistance of noradrenaline in blood vessels to depletion by 6‐hydroxydopamine or immunosympathectomy

Berkowitz¹,

Spector²,

Tarver³

1972

British J Pharmacology

View full text Add to dashboard Cite

Summary1. The degree of the decrease in the noradrenaline concentrations caused by 6-hydroxydopamine or immunosympathectomy was different in different areas of the cardiovascular system. 2. In rats or guinea-pigs 6-hydroxydopamine depleted the noradrenaline content of the heart by 90%, of the mesenteric vein by 80% and of the mesenteric artery and aorta by 30-60%. Immunosympathectomy elicited a 70% reduction in the cardiac noradrenaline but only a 50% reduction in the noradrenaline of the blood vessels of the rat. 3. The tyrosine hydroxylase activity of the heart, blood vessels, or adrenal glands was not significantly altered 2 weeks after 6-hydroxydopamine. Nor was the monoamine oxidase activity in heart or blood vessels changed. 4. The inconsistent ability of both 6-hydroxydopamine and immunosympathectomy to abolish experimental hypertension may be due to the partial persistence of noradrenaline and functional sympathetic nervous system activity in the blood vessels.

show abstract

Section: Methodsmentioning

confidence: 99%

Resistance of noradrenaline in blood vessels to depletion by 6‐hydroxydopamine or immunosympathectomy

Berkowitz¹,

Spector²,

Tarver³

1972

British J Pharmacology

View full text Add to dashboard Cite

show abstract

“…The specimens were weighed on a Cahn Electrobalance (sensitivity, ~ 50 ng) equipped with a humidified chamber to prevent drying of the tissues. All samples were placed in glass homogenizers containing 0.2~ Triton X-100 and kept on ice until assayed for TH activity, which was performed according to the method described by Nagatsu et al 19. The principle of this method relies on the recovery and measurement of tritiated water produced during the hydroxylation of L-[3,5-ZH]tyrosine.…”

Section: (Accepted May 5th 1979)mentioning

confidence: 99%

Reciprocal modulation of tyrosine hydroxylasea activity in rat carotid body

et al. 1979

View full text Add to dashboard Cite

The carotid body is an arterial chemoreceptor organ responsive to blood levels of pO2, pCOe and pH 13. The parenchymal tissue of the carotid body is composed mainly of two cell types: the glomus or Type I cells, which are disposed together in groups or glomeruli, and the sustentacular or Type II cells, which appear as glial-like elements enclosing the glomeruli in capsular fashion 3,4. The Type I cells, which have abundant dense-cored vesicles and are known to contain catecholaminesl, 2,11,15, receive a sensory innervation from afferent fibers of the carotid sinus nerve 3. Recent studies have also shown the presence of reciprocal synapses at these junctions between afferent nerve terminals and Type I cells TM. In addition, these cells receive an efferent innervation from both preganglionic and postganglionic sympathetic fibers which reach the carotid body from the superior cervical ganglion 18.The principal catecholamine in the Type I cells of the rat carotid body is dopamine (63 ~), the remainder being norepinephrine 11. Although the precise role of catecholamines in the carotid body remains to be elucidated, there is evidence implicating these substances as neurotransmitters or modulators of chemoreceptor activity 5,6,16,~7,2°,24. Of particular interest are the recent findings in rat carotid body that hypoxia induces a long-term increase in tyrosine hydroxylase (TH) activity, the rate-limiting enzyme in catecholamine biosynthesis 7,9. In these experiments, unanesthetized animals were exposed in a chamber for variable times to low 02 atmospheres. When TH activity was assayed 48 h following the hypoxic episode there was an increase in enzyme activity of 50-80 ~ above control values (control animals were exposed only to room air in the chamber). This long-term induction of TH could have resulted from either direct action by the hypoxic stimulus upon the Type I cells of the carotid body, or instead it might have arisen reflexy via the nervous innervation to the organ. TH activity in other catecholaminergic systems is known to be subject to neural controlS,14,21, 22, and as described above the Type I cells of the carotid body receive a complex nervous innervation (afferent, efferent and reciprocal synapses). It is thus

show abstract

“…Although polyanions, such as heparin and dextran sulfate, markedly stimulated the activity of crude enzyme by increasing the V , they were much less effective in the activation of purified enzyme. A marked stimulation of the enzyme activity by phospholipids, such as phosphatidylserine, phosphatidylinositol, phosphatidylcholine and phosphatidylethanolamine, were not observed in both pure and crude preparations even at low concentrations of the pterin cofactor.Tyrosine 3-monooxygenase [L-tyrosine, tetrahydropteridine : oxygen oxidoreductase (3-hydroxylating)] catalyzes the conversion of tyrosine to 3,4-dihydroxyphenylalanine, which is the initial and rate-limiting step in the biosynthesis of catecholamines such as dopamine, norepinephrine and epinephrine [1,2]. …”

mentioning

confidence: 99%

mentioning

confidence: 99%

“…Tyrosine 3-monooxygenase [L-tyrosine, tetrahydropteridine : oxygen oxidoreductase (3-hydroxylating)] catalyzes the conversion of tyrosine to 3,4-dihydroxyphenylalanine, which is the initial and rate-limiting step in the biosynthesis of catecholamines such as dopamine, norepinephrine and epinephrine [1,2]. A number of attempts to purify and characterize the enzyme had not been successful because of its lability and its tendency to aggregate during purification, until Markey et al [3] succeeded in obtaining pure form from cultured rat pheochromocytoma cells.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Purification and Some Properties of Tyrosine 3‐Monooxygenase from Rat Adrenal

Okuno

Fujisawa

1982

European Journal of Biochemistry

View full text Add to dashboard Cite

Tyrosine 3-monooxygenase was purified to homogeneity, as judged by sodium dodecyl sulfate/polyacrylamide gel electrophoresis, from rat adrenal. The specific activity of the final preparation was approximately 1600 nmol min-' mg protein-', which was much higher than the highest yet reported. The enzyme was markedly stabilized in the presence of glycerol, Tween 80 and EDTA. As judged by gel filtration on Ultrogel AcA 34, sodium dodecyl sulfate/polyacrylamide gel electrophoresis and cross-linking studies, the enzyme appeared to be composed of four identical subunits, each possessing a molecular weight of 59000. The isoelectric point of the enzyme was estimated to be 6.7 in the presence of 8 M urea and 6.6 in its absence. Amino acid analysis of the enzyme revealed a fairly high content of serine residues in this protein.Purification of the enzyme caused changes in the kinetic properties of the enzyme. The K,,, for 2-amino-4-hydroxy-6-methyl-5,6,7,8-tetrahydropteridine decreased from 220 pM to 58 pM. The pH profile for the enzyme activity became more broad and the pH optimum was changed from an acid pH to a neutral pH. Although polyanions, such as heparin and dextran sulfate, markedly stimulated the activity of crude enzyme by increasing the V , they were much less effective in the activation of purified enzyme. A marked stimulation of the enzyme activity by phospholipids, such as phosphatidylserine, phosphatidylinositol, phosphatidylcholine and phosphatidylethanolamine, were not observed in both pure and crude preparations even at low concentrations of the pterin cofactor.Tyrosine 3-monooxygenase [L-tyrosine, tetrahydropteridine : oxygen oxidoreductase (3-hydroxylating)] catalyzes the conversion of tyrosine to 3,4-dihydroxyphenylalanine, which is the initial and rate-limiting step in the biosynthesis of catecholamines such as dopamine, norepinephrine and epinephrine [1,2].

show abstract

A rapid and simple radioassay for tyrosine hydroxylase activity

Cited by 574 publications

References 3 publications

Resistance of noradrenaline in blood vessels to depletion by 6‐hydroxydopamine or immunosympathectomy

Resistance of noradrenaline in blood vessels to depletion by 6‐hydroxydopamine or immunosympathectomy

Reciprocal modulation of tyrosine hydroxylasea activity in rat carotid body

Purification and Some Properties of Tyrosine 3‐Monooxygenase from Rat Adrenal

Contact Info

Product

Resources

About