Relation of glucose tolerance factor to impaired intravenous glucose tolerance of rats on stock diets

1959 ◽  
Vol 196 (3) ◽  
pp. 614-618 ◽  
Author(s):  
Walter Mertz ◽  
Klaus Schwarz
Keyword(s):  
Glucose Tolerance ◽  
Water Soluble ◽  
Tolerance Factor ◽  
Brewer’S Yeast ◽  
Removal Rates ◽  
Intravenous Glucose ◽  
Brewer's Yeast ◽  
Intravenous Glucose Tolerance ◽  
Low Glucose ◽  
Glucose Tolerance Factor

Intravenous glucose tolerance tests were made on male Sprague-Dawley rats, raised on different diets. Two natural diets (McCollum's wheat-casein ration and table scraps) produced glucose removal rates of around 4%/min. or more. In rats raised on three commercial pelleted stock rations (Purina, Hunt Club, Rockland) as well as on a semipurified Torula yeast diet, low glucose removal rates of 2.5–2.8%/min. were consistently detected after 20 or more days of feeding. The results are related to the contents, in the investigated diets, of the glucose tolerance factor (GTF), a recently described, water soluble dietary agent of low molecular weight. Development of low glucose removal rates is prevented by dietary supplementation with brewer's yeast, or with GTF concentrates from brewer's yeast or pork kidney powder. The fully developed impairment is cured within 1–2 weeks by the addition of GTF concentrates to the diet. It is also reconstituted to normal within 18 hours after stomach tubing of GTF fractions of widely different degrees of purification. This curative procedure is being used as a 24-hour test for GTF.

Preparation of chromium-containing material of glucose tolerance factor activity from brewer's yeast extracts and by synthesis

1977 ◽  
Vol 25 (1) ◽  
pp. 162-166 ◽  
Author(s):  
Edward W. Toepfer ◽  
Walter Mertz ◽  
Marilyn M. Polansky ◽  
Edward E. Roginski ◽  
Wayne R. Wolf
Keyword(s):  
Glucose Tolerance ◽  
Tolerance Factor ◽  
Factor Activity ◽  
Brewer’S Yeast ◽  
Brewer's Yeast ◽  
Glucose Tolerance Factor

scholarly journals Effects of extracts of high- and low-chromium brewer's yeast on metabolism of glucose by hepatocytes from rats fed on high- or low-Cr diets

1990 ◽  
Vol 63 (3) ◽  
pp. 623-630 ◽  
Author(s):  
E. S. Holdsworth ◽  
E. Neville
Keyword(s):  
Glucose Tolerance ◽  
Defined Medium ◽  
Normal Diet ◽  
Tolerance Factor ◽  
Brewer’S Yeast ◽  
Brewer's Yeast ◽  
Beneficial Effects ◽  
Cr Content ◽  
Glycogen Synthetase ◽  
Glucose Tolerance Factor

Brewer's yeast was grown on a defined medium containing glucose, ammonia, salts and vitamins plus tracer 51Cr without (low-Cr) or with (high-Cr) carrier Cr. The two batches of yeast differed by more than 100-fold in Cr content, containing 80 ng and 10 7mu;g Cr/g dry yeast respectively. Extraction and fractionation procedures were designed to isolate Cr complexes with properties similar to those reported for glucose tolerance factor. After weaning, rats were reared on rat cubes (normal diet) or on a diet containing less than 0.1 μg Cr/kg (low-Cr diet), or on the low-Cr diet supplemented with Cr (1 mg Cr/kg). Hepatocytes from these rats were incubated with [U-14C]glucose and incorporation of 14C into glycogen was measured. Incorporation of glucose-C into glycogen was enhanced by some yeast fractions in the presence of insulin, but had less effect in the absence of insulin. No difference could be detected between the responses to fractions from high- or low-Cr yeast extracts, or between responses by hepatocytes from animals fed on normal or low-Cr diets with or without Cr upplementation. Glycogen synthetase (EC 2.4.1.11) activity (total and percentage in the a form) was similar in hepatocytes isolated from animals on the normal and low-Cr diets. Those yeast fractions which enhanced the response to insulin in the 14C-incorporation experiments also enhanced the percentage of the enzyme in the a form in the presence of insulin, but not in the absence of insulin. The presence in yeast extracts of material which enhances the response to insulin by hepatocytes may help to explain the reported beneficial effects of dietary yeast supplements on glucose tolerance.

APPLICATION DE LA DOUBLE ÉPREUVE D'HYPERGLYCÉMIE INTRAVEINEUSE À L'ÉTUDE DU DIABÈTE

1960 ◽  
Vol XXXIII (II) ◽  
pp. 157-167
Author(s):  
T. Rodari ◽  
G. Specchia
Keyword(s):  
Glucose Tolerance ◽  
Pancreatic Islet ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Intravenous Glucose ◽  
Intravenous Glucose Tolerance ◽  
Glucose Assimilation

ABSTRACT The double intravenous glucose tolerance test does not modify the assimilation coefficient in normal and thin diabetic subjects. On the contrary, in fat diabetic subjects the second coefficient of assimilation increases significantly, but not the first one. From these researches it is evident that the valuation of glucose assimilation by double venous hyperglycaemic test indicates the functional behaviour of the pancreas in different diabetic states. The interpretation of this behaviour of pancreatic islet response to the double venous hyperglycaemic test is discussed.

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