SOME CHARACTERISTICS OF BRAIN TYROSINE HYDROXYLASE

1967 ◽  
Vol 45 (10) ◽  
pp. 1557-1563 ◽  
Author(s):  
E. G. McGeer ◽  
S. Gibson ◽  
P. L. McGeer
Keyword(s):  
Tyrosine Hydroxylase ◽  
Rat Brain ◽  
Phosphate Buffer ◽  
Sodium Acetate ◽  
Acetate Buffer ◽  
Sodium Acetate Buffer ◽  
Optimum Conditions ◽  
Hydroxylase Activity ◽  
Michaelis Constant ◽  
Brain Tyrosine Hydroxylase

Tyrosine hydroxylase from brain homogenates differed from tyrosine hydroxylase from adrenal homogenates in being particle-bound, insensitive to cofactors, possessing a lower Michaelis constant for tyrosine, and being responsive to slightly different optimum conditions of pH and buffer. The combination of 0.02 M mercaptoethanol and 0.1–1.0 mM 2-amino-4-hydroxy-6,7-dimethyltetrahydropteridine (DMPH4) increased tyrosine hydroxylase activity in beef adrenal homogenates 15-fold, but was without effect on activity in rat brain homogenates. The Km for tyrosine in beef adrenal homogenates was 4 × 10−6 M, and in rat brain homogenates was 0.45 × 10−6 M. Conversion in beef adrenal homogenates was maximum in 0.6 M sodium acetate buffer, pH 6.0, and in rat brain homogenates was maximum in 0.28 M phosphate buffer, pH 6.2.

Sodium Acetate Buffer

1975 ◽  
Vol 33 (02) ◽  
pp. 226-229 ◽  
Author(s):  
I. S Chohan ◽  
J Vermylen ◽  
I Singh ◽  
K Balakrishkan ◽  
M Verstraete
Keyword(s):  
Low Temperature ◽  
Phosphate Buffer ◽  
Sodium Acetate ◽  
Acetate Buffer ◽  
Clot Lysis ◽  
Sodium Acetate Buffer ◽  
End Point ◽  
Lysis Time ◽  
Clot Lysis Time

SummarySodium acetate buffer, 0.12 M, pH 7.4 as a diluent in the low temperature technique of dilute clot lysis time, is more effective in accelerating the velocity of lysis than phosphate buffer of similar pH and molarity. A uniform shape of the clot is maintained throughout the digestion in sodium acetate buffer and the end point of lysis is characteristically marked by an abrupt and sharply defined disintegration. Sodium acetate buffer can be employed advantageously in this technique not only to improve the observation but also to shorten the lysis times.

Fibrinolytic Activity at High Altitude and Sodium Acetate Buffer

1974 ◽  
Vol 32 (01) ◽  
pp. 065-070 ◽  
Author(s):  
I. S Chohan ◽  
I Singh ◽  
K Balakrihsnan
Keyword(s):  
High Altitude ◽  
Pulmonary Oedema ◽  
Phosphate Buffer ◽  
Fibrinolytic Activity ◽  
Sodium Acetate ◽  
Acetate Buffer ◽  
Clot Lysis ◽  
Protective Mechanism ◽  
Sodium Acetate Buffer ◽  
Lysis Time

SummaryAt high altitude there is a tendency for fibrinolytic activity to be enhanced depending, perhaps, on the duration of exposure and this seems to be a protective mechanism against the development of high altitude pulmonary oedema which is associated with diminished fibrinolytic activity. The fibrinolytic response at high altitude seems to be fluctuated during the process of acclimatisation though being maintained at a plateau higher than that in the plains. It apparently results from hypoxic stress but more likely reflects the physiological response to the hypercoagulable state at high altitude. As clot lysis times in high altitude pulmonary oedema are unusually prolonged an attempt at shortening their observation in the test system is desirable. Sodium acetate, 0.12 M solution with pH 7.4 as a diluent in the low temperature technique of dilute clot lysis time is potentially effective to accelerate the lysis time by approximately 33 % compared to phosphate buffer solution of similar pH and molarity. Also the end point of disintegration of clot is more abrupt and sharply defined. Sodium acetate buffer can advantageously replace phosphate buffer as a diluent in this technique.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

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