Determination of phenylalanine hydroxylase activity in liver tissue

1970 ◽  
Vol 69 (5) ◽  
pp. 596-598
Author(s):  
A. A. Pokrovskii ◽  
N. T. Usacheva ◽  
G. N. Milova ◽  
M. V. Ermolaev ◽  
A. S. Ermolov
Keyword(s):  
Liver Tissue ◽  
Phenylalanine Hydroxylase ◽  
Hydroxylase Activity

Comparison of Different Methods for the Determination of Phenylalanine Hydroxylase Activity in Rat Liver and Euglena gracilis

1984 ◽  
Vol 39 (7-8) ◽  
pp. 728-733 ◽  
Author(s):  
Rita M. Fink ◽  
Erich F. Elstner
Keyword(s):  
Rat Liver ◽  
Euglena Gracilis ◽  
Phenylalanine Hydroxylase ◽  
Hplc Method ◽  
Enzymic Activity ◽  
Hydroxylase Activity ◽  
Product Separation ◽  
Tyrosine Concentration ◽  
Layer Chromatography

Abstract Three different methods for the determination of phenylalanine hydroxylase activity have been compared: a) Differential photometric assay of the increase in tyrosine concentration in the presence of phenylalanine; b) Product separation by thin layer chromatography and scintillation counting of the [14C]tyrosine formed;c) HPLC separation and spectrofluorometric quantification of derivatized amino acids. A comparison of the activities of phenylalanine hydroxylase in rat liver and Euglena gracilis clearly showed that only rat liver contains this enzymic activity as shown by methods b) and c) although pseudo-activity of Euglena gracilis preparations was found during the spectrophotometric test a). The HPLC method proved to be the fastest, most reliable and convenient method for direct tyrosine determination and thus for measuring phenylalanine hydroxylase activity.

scholarly journals The quantitative determination of phenylalanine hydroxylase in rat tissues. Its developmental formation in liver

1972 ◽  
Vol 127 (4) ◽  
pp. 669-674 ◽  
Author(s):  
Margaret M. McGee ◽  
Olga Greengard ◽  
W. Eugene Knox
Keyword(s):  
Phenylalanine Hydroxylase ◽  
Mitochondrial Fraction ◽  
Kinetic Properties ◽  
Rat Tissues ◽  
Hydroxylase Activity ◽  
Kidney Enzyme ◽  
Distribution Studies ◽  
Similar Kinetic ◽  
Reduced State

A sensitive method was developed for determining the phenylalanine hydroxylase activity of crude tissue preparations in the presence of optimum concentrations of the 6,7-dimethyl-5,6,7,8-tetrahydropterin cofactor (with ascorbate or dithiothreitol to maintain its reduced state) and substrate. Tissue distribution studies showed that, in addition to the liver, the kidney also contains significant phenylalanine hydroxylase activity, one-sixth (in rats) or half (in mice) as much per g as does the liver. The liver and the kidney enzyme have similar kinetic properties; both were located in the soluble phase and were inhibited by the nucleo-mitochondrial fraction. Phenylalanine hydroxylase, like most rat liver enzymes concerned with amino acid catabolism, develops late. On the 20th day of gestation, the liver (and the kidney) is devoid of phenylalanine hydroxylase and at birth contains 20% of the adult activity. During the second postnatal week of development, when the phenylalanine hydroxylase activity was about 40% of the adult value, an injection of cortisol doubled this value. Cortisol had no significant effect on phenylalanine hydroxylase in adult liver or on phenylalanine hydroxylase in kidney at any age.

Development of phenylalanine hydroxylase activity in guinea pig liver

1972 ◽  
Vol 261 (2) ◽  
pp. 315-320 ◽  
Author(s):  
Helen K. Berry ◽  
Roberta Cripps ◽  
Kay Nicholls ◽  
David McCandless ◽  
Calvin Harper
Keyword(s):  
Guinea Pig ◽  
Phenylalanine Hydroxylase ◽  
Hydroxylase Activity ◽  
Pig Liver ◽  
Guinea Pig Liver

scholarly journals Determination of the optical properties of bovine liver tissue using integrating sphere technique

2018 ◽  
Vol 1 (1) ◽  
pp. 248-252
Author(s):  
Halil Arslan ◽  
Yasar Baris Dolukan
Keyword(s):  
Optical Properties ◽  
Liver Tissue ◽  
Tissue Sample ◽  
Bovine Liver ◽  
Integrating Sphere ◽  
Scattering Coefficients ◽  
Single Sphere ◽  
Microscope Slides ◽  
Good Agreement

The optical properties (absorption and reduced scattering coefficients, µa and µs’) of bovine liver tissue for 635 nm has been determined by using integrating sphere and inverse adding-doubling (IAD) techniques. For this purpose, total reflectance and total transmittance values of bovine liver tissue sample, which is placed between two microscope slides, have been measured by using single-sphere system. The measured values have been used as input parameters for IAD program to extract the µa and µs’ of the sample. In this study, µa and µs’ of bovine liver tissue for 635 nm have been determined to be 0.22 mm-1 and 0.51mm-1, respectively. These values, which yield 1.44 mm penetration depth, are in good agreement with the ones in the literature.

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