Effect of Zein Diets on Nitrogen Content of Hymenolepis diminuta and on Rat Liver Protein Nitrogen

1967 ◽  
Vol 53 (4) ◽  
pp. 688 ◽  
Author(s):  
David F. Mettrick
Keyword(s):  
Nitrogen Content ◽  
Rat Liver ◽  
Hymenolepis Diminuta ◽  
Liver Protein ◽  
Protein Nitrogen

Insulin stimulus of leucine incorporation into frog liver protein

1962 ◽  
Vol 203 (4) ◽  
pp. 687-689 ◽  
Author(s):  
J. C. Penhos ◽  
M. E. Krahl
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Leucine Incorporation ◽  
Liver Protein ◽  
Amino Acid Incorporation ◽  
Insulin Effect ◽  
Acid Incorporation ◽  
Liver Slices ◽  
Stimulation Of

Slices prepared from livers of bull frogs ( Rana catesbiana), pancreatectomized and/or hypophysectomized 7 days before, were incubated 2 hr in frog Ringer-bicarbonate solution at 25 C. Incorporation of leucine-1-C14 into protein was subnormal in the pancreatectomized series. The addition of insulin in vitro, with glucose also present in the medium, produced a significant ( P < 0.01) stimulation of amino acid incorporation in the following series: livers from normal fed animals; livers from animals pancreatectomized 7 days before; and livers from animals pancreatectomized and hypophysectomized 7 days before. Neither insulin nor glucose alone gave a significant effect. These results therefore confirm and extend those obtained with rat liver slices showing that insulin can stimulate amino acid incorporation into protein when added directly to liver. The effect is relatively greatest with livers from animals pancreatectomized 7 days before; the insulin effect does not depend on the presence of the pituitary, as it is obtainable with livers from animals hypophysectomized and pancreatectomized 7 days previously.

Modulation of Rat Liver Protein Kinase C during in Vivo CC14-Induced Oxidative Stress

1993 ◽  
Vol 194 (2) ◽  
pp. 635-641 ◽  
Author(s):  
M.A. Pronzato ◽  
C. Domenicotti ◽  
E. Rosso ◽  
A. Bellocchio ◽  
M. Patrone ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Rat Liver ◽  
Liver Protein ◽  
Kinase C

scholarly journals Polyribosomes in isolated liver cells. Preparative procedures, effects of incubation and correlation with protein synthesis

1980 ◽  
Vol 186 (1) ◽  
pp. 35-45 ◽  
Author(s):  
A J Dickson ◽  
C I Pogson
Keyword(s):  
Protein Synthesis ◽  
Rat Liver ◽  
Isolated Hepatocytes ◽  
Liver Cells ◽  
Liver Protein ◽  
Isolated Cells ◽  
Isolated Liver Cells ◽  
Rat Liver Cells ◽  
Isolated Liver

Methods have been derived which permit the isolation of undergraded polyribosomes from isolated rat liver cells. Under the conditions used the polyribosome profile of hepatocytes immediately after isolation was essentially identical with that from intact liver. However, during incubation of cells in complex physiological media there was a progressive dissociation of polyribosomes. The addition of a variety of factors that produce reaggregation of polyribosomes in rat liver in vivo did not prevent dissociation during cell incubations. Although large polyribosomes were lost most rapidly, the albumin-synthesizing capacity of isolated cells was not selectively lost when compared with total protein synthesis. The significance of these results for the use of isolated hepatocytes in the study of liver protein synthesis is discussed.

Direct and Indirect Determination of True Protein Content of Milk by Kjeldahl Analysis: Collaborative Study

1991 ◽  
Vol 74 (2) ◽  
pp. 281-288 ◽  
Author(s):  
David M Barbano ◽  
Joanna M Lynch ◽  
J Richard Fleming
Keyword(s):  
Nitrogen Content ◽  
Protein Content ◽  
Total Nitrogen ◽  
Collaborative Study ◽  
Total Nitrogen Content ◽  
Nonprotein Nitrogen ◽  
Protein Nitrogen ◽  
Nitrogen Determination ◽  
True Protein

Abstract Currently, the reference procedure for determination of the "protein" content of milk is based on measurement of the total nitrogen content of milk by the Kjeldahl method (AOAC method, 920.105). About 6% of the total nitrogen content of milk Is nonprotein nitrogen. Therefore, total nitrogen multiplied by the conversion factor 6.38 overestimates the true protein content of milk on average by about 6%. In the present study, new direct and Indirect methods were developed for measurement of the true protein content of whole milk by Kjeldahl nitrogen determination. Both new methods are sample preparation procedures used to fractionate the nitrogen-containing compounds In milk prior to measurement of the nitrogen content of these fractions by Kjeldahl analysis. The collaborative study consisted of 9 pairs of blind duplicate milk samples that were analyzed for total nitrogen, nonprotein nitrogen, and protein nitrogen by each of 10 laboratories. Both methods for true protein measurement (direct and Indirect) gave acceptable statistical performance characteristics and good agreement between methods. The new direct method requires about half the laboratory analysis work of the indirect method (i.e., total minus nonprotein nitrogen). The methods have been adopted official first action by AOAC as (1) a new method for nonprotein nitrogen determination in milk, (2) a new method (direct) for determination of protein nitrogen content of milk, and {3) an alternative method (indirect) for determination of protein nitrogen content of milk.

Variation of Total Nitrogen, Non-protein Nitrogen Content, and Types of Alkaloids at Different Stages of Development inErythrina americanaSeeds†

1996 ◽  
Vol 44 (10) ◽  
pp. 2987-2991 ◽  
Author(s):  
R. García-Mateos ◽  
B. Lucas ◽  
M. Zendejas ◽  
M. Soto-Hernández ◽  
M. Martínez ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Total Nitrogen ◽  
Stages Of Development ◽  
Protein Nitrogen

scholarly journals Measurement of protein turnover in rat liver. Analysis of the complex curve for decay of label in a mixture of proteins

1976 ◽  
Vol 156 (3) ◽  
pp. 657-663 ◽  
Author(s):  
P J Garlick ◽  
J C Waterlow ◽  
R W Swick
Keyword(s):  
Rat Liver ◽  
Turnover Rate ◽  
Decay Curve ◽  
Specific Radioactivity ◽  
Liver Protein ◽  
Turnover Rates ◽  
A Value ◽  
Maximum Value ◽  
Single Exponential

The curve for decay of 14C in rat liver protein labelled by injection of NaH14CO3 was analysed to obtain the average turnover rate of mixed liver protein. Three different methods of analysis were used. (1) Unlike decay curves from homogeneous proteins, the curve did not fit a single exponential, but a good fit was obtained with three exponentials. By assuming that the mixture contained three major components with different turnover rates, the calculated value for the average turnover rate (k) was close to 40% per day. (2) k was also calculated from the area under the decay curve, a method which makes no assumptions about the number of proteins in the mixture. This method also gave a value close to 40% per day. (3) It was shown empirically, both by simulation of decay of label in model mixtures of protein and with the decay curve measured in vivo, that k can be calculated from the time taken for the specific radioactivity to fall to 10% of its maximum value. This is an advantage, since the other two methods require the decay curve to be measured over a much longer period of time.

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