IMPAIRMENT OF PLASMA GLYCOPROTEIN SYNTHESIS IN EARLY CHOLINE DEFICIENCY

1966 ◽  
Vol 44 (7) ◽  
pp. 1064-1067 ◽  
Author(s):  
Sailen Mookerjea
Keyword(s):  
Choline Deficiency ◽  
Glycoprotein Synthesis ◽  
Plasma Glycoprotein

Impairment of plasma glycoprotein synthesis in choline deficiency compared with effects of carbon tetrachloride intoxication

1968 ◽  
Vol 46 (3) ◽  
pp. 499-505 ◽  
Author(s):  
Sailen Mookerjea
Keyword(s):  
Carbon Tetrachloride ◽  
Plasma Proteins ◽  
Specific Radioactivity ◽  
Starch Gel Electrophoresis ◽  
Choline Deficiency ◽  
Deficient Diet ◽  
Glycoprotein Synthesis ◽  
Carbon Tetrachloride Intoxication ◽  
Starch Gel ◽  
Plasma Glycoprotein

The incorporation of glucosamine-1-14C into plasma proteins is impaired in rats within 2 days when they are fed a choline-deficient diet. Separation of plasma proteins by starch-gel electrophoresis, and autoradiography of the dried gels, showed four labelled areas (glycoproteins). In choline deficiency there was visual evidence of depletion of radioactivity in the fast α-globulin area, a finding confirmed by the specific radioactivity of proteins eluted from electrophoretic zones of the starch gel. Within 4 h after ingestion of carbon tetrachloride, the synthesis of plasma glycoprotein was reduced by 90% and labelling of all four glycoprotein areas on dried starch gel autoradiograms virtually ceased. The results suggest that the defect in glycoprotein synthesis in carbon tetrachloride intoxication is nonspecific, whereas in choline deficiency the impairment is specific and localized in the fast α-globulin fraction. The results suggest a limiting role of a glycoprotein in the pathway of plasma lipoprotein synthesis.

STUDIES ON THE SYNTHESIS OF PLASMA GLYCOLIPOPROTEIN AND HEPATIC SUB-CELLULAR GLYCOPROTEIN IN EARLY CHOLINE DEFICIENCY

1967 ◽  
Vol 45 (6) ◽  
pp. 825-838 ◽  
Author(s):  
Sailen Mookerjea ◽  
David Jeng ◽  
Judith Black
Keyword(s):  
Liver Microsome ◽  
Specific Radioactivity ◽  
Plasma Lipoproteins ◽  
Residual Fraction ◽  
Choline Deficiency ◽  
Glycoprotein Synthesis ◽  
Limiting Step ◽  
Residual Protein ◽  
Lipoprotein Synthesis ◽  
Smooth Membrane

Impairment of glycoprotein synthesis in trichloroacetic acid insoluble and in residual protein (d > 1.21) fractions of plasma in early choline deficiency has been confirmed. Plasma lipoproteins of d < 1.006, 1.006–1.063, and 1.063–1.21 are also rapidly labelled after intraperitoneal injection of glucosamine-1-14C. In general, there was no difference in specific radioactivity of plasma glycolipoproteins between choline-supplemented rats and rats deprived of choline for 2 days during 180 min of incorporation.Incorporation of glucosamine-1-14C into microsomal glycoprotein is significantly impaired in early choline deficiency. Further sub-microsomal fractionation produced evidence that the site of impairment of glycoprotein synthesis is in the smooth microsome portion. These studies suggest that a decreased synthesis of glycoprotein(s) in liver-microsome smooth membrane and in the plasma residual fraction (d > 1.21) may represent an impairment of 'lipoprotein precursor protein' synthesis in early choline deficiency. An inhibition of this limiting step would possibly impair the rate of plasma lipoprotein synthesis, leading to the development of fatty liver in choline deficiency.

The Use of Nucleotide-Sugar: Glycoprotein Glycosyltransferases to Assess Golgi Apparatus Function in Morris Hepatomas

1971 ◽  
Vol 49 (1) ◽  
pp. 61-70 ◽  
Author(s):  
R. L. Hudgin ◽  
R. K. Murray ◽  
L. Pinteric ◽  
H. P. Morris ◽  
H. Schachter
Keyword(s):  
Golgi Apparatus ◽  
Rat Liver ◽  
Nucleotide Sugar ◽  
Glycoprotein Synthesis ◽  
Enzymatic Assays ◽  
Tumor Bearing ◽  
Normal Rat ◽  
Liver Homogenates ◽  
Plasma Glycoprotein ◽  
Slow Growing

Enzymatic assays for CMP-sialic acid: glycoprotein sialyltransferase and UDP-N-acetylglucosamine: glycoprotein N-acetylglucosaminyltransferase were performed on crude homogenates of three Morris hepatomas (7777, 7800, and 5123D), and on liver homogenates from the host animals and normal Buffalo strain rats. It was found that sialyltransferase activities were greatly decreased in the most rapidly growing tumor (hepatoma 7777) and were decreased to a lesser extent in the more slowly growing hepatoma 7800; enzyme activities in hepatoma 5123D, another relatively slow growing tumor, were not significantly different from control values. Sialyltransferase activities were significantly elevated in the livers of all the tumor-bearing animals and were especially high in the livers of animals carrying hepatoma 7777; these elevations may be related to increased plasma glycoprotein synthesis by liver secondary to the inflammatory stimulus generated by the tumors. In contrast to the sialyltransferase analyses, N-acetylglucosaminyltransferase activities in tumor homogenates were very similar to control values for all three hepatomas. When the data are expressed as ratios of sialyltransferase activity to N-acetylglucosaminyltransferase activity, two of the three tumors show highly significant decreases of this ratio compared to either control or host livers. Since these glycosyltransferases have previously been shown to be located in the Golgi apparatus of normal rat liver where they function in the biosynthesis of glycoproteins, the above results have been interpreted to indicate a shift in the function of the Golgi apparatus in certain Morris hepatomas as compared to normal livers. Finally, glycosyltransferase assays and electron microscopy have been used to demonstrate the feasibility of preparing Golgi-enriched fractions from all three hepatomas by methods previously applied to normal rat liver.

PLASMA GLYCOPROTEIN SYNTHESIS IN ALLOXAN-DIABETIC RATS

1971 ◽  
Vol 50 (2) ◽  
pp. 355-356 ◽  
Author(s):  
S. V. CAPREOL ◽  
L. E. SUTHERLAND ◽  
D. A. HANIMYAN
Keyword(s):  
Diabetic Rats ◽  
Glycoprotein Synthesis ◽  
Plasma Glycoprotein

Mitochondrial Changes in Choline-Deficient Rat Myocardium

1968 ◽  
Vol 26 ◽  
pp. 112-113
Author(s):  
F. G. Zaki
Keyword(s):  
Muscle Fibers ◽  
Liver Mitochondria ◽  
Ultrastructural Changes ◽  
Choline Deficiency ◽  
Nutritional Disorder ◽  
Low Protein ◽  
Structural Abnormalities ◽  
Cross Striation ◽  
Pericardial Edema ◽  
Myocardial Lesions

Choline-deficiency was induced in Holtzman young rats of both sexes by feeding them a high fat - low protein diet.Preliminary studies of the ultrastructural changes in the myocardium of these animals have been recently reported from this laboratory. Myocardial lesions first appeared in the form of intraventricular mural thrombi, loss of cross striation of muscle fibers and focal necrosis of muscle cells associated with interstitial myocarditis. Prolonged choline-deficiency induced cardiomegaly associated with pericardial edema.During the early phase of this nutritional disorder, heart mitochondria - despite of not showing any swelling similar to that usually encountered in liver mitochondria of the same animal - ware the most ubiquitous site of marked structural abnormalities. Early changes in mitochondria appeared as vacuolation, disorganization, disruption and loss of cristae. Degenerating mitochondria were often seen quite enlarged and their matrix was replaced by whorls of myelin figures resembling lysosomal structures especially where muscle fibers were undergoing necrosis. In some areas, mitochondria appeared to be unusually clumped together where some contained membranelined vacuoles and others enclosed dense bodies and granular inclusions.

Hypertension produced by choline deficiency in rats

Pathology ◽  
1970 ◽  
Vol 2 (2) ◽  
pp. 125-131 ◽  
Author(s):  
C.C. Kratzing ◽  
G.A. Wetzig ◽  
M. Boland
Keyword(s):  
Choline Deficiency
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