Intrinsic factor studies: II. The effect of gastric juice on the urinary excretion of radioactivity after the oral administration of radioactive vitamin B12

2004 ◽  
Vol 144 (5) ◽  
pp. 268-272 ◽  
Author(s):  
Robert F. Schilling
Keyword(s):  
Oral Administration ◽  
Urinary Excretion ◽  
Vitamin B12 ◽  
Gastric Juice ◽  
Intrinsic Factor

scholarly journals On the Nature of Castle’s Hemopoietic Factor

Blood ◽  
1951 ◽  
Vol 6 (12) ◽  
pp. 1234-1239 ◽  
Author(s):  
SHEILA T. CALLENDER ◽  
L. G. LAJTHA
Keyword(s):  
Vitamin B12 ◽  
Gastric Juice ◽  
Intrinsic Factor ◽  
Normal Serum ◽  
Relationship Of ◽  
The Relationship

Abstract 1. Normal gastric juice (intrinsic factor) and vitamin B12 together form a thermolabile hemopoietic factor which ripens megaloblasts in vitro, both gastric juice and B12 alone being inactive. 2. The hemopoietic factor in normal serum which ripens megaloblasts in vitro also appears to be thermolabile, heating to 56 C. for 2 hours destroying some of its activity. 3. The relationship of these factors is discussed and an extra-gastric as well as a gastric source of intrinsic factor is postulated.

scholarly journals Time Pattern of Vitamin B12Co60 Urinary Excretion in Man After Oral Administration and Parenteral "Flushing"

Blood ◽  
1956 ◽  
Vol 11 (4) ◽  
pp. 352-356 ◽  
Author(s):  
WILLIAM R. BEST ◽  
WENDELL A. LANDMANN ◽  
LOUIS R. LIMARZI
Keyword(s):  
Oral Dose ◽  
Oral Administration ◽  
Urinary Excretion ◽  
Pernicious Anemia ◽  
Intrinsic Factor ◽  
Time Pattern ◽  
Number Of Patients ◽  
Excretion Rates ◽  
The Individual ◽  
Factor Concentrate

Abstract Serial urine collections in a number of patients with pernicious anemia given 2 µg B12Co60 orally followed in two hours by 1000 µg nonradioactive vitamin B12 showed little urinary radioactivity at any time. When these tests were repeated together with a potent oral dose of intrinsic factor concentrate, there was little activity during the first four hours. Peak excretion rates occurred most commonly between 6 and 12 hours after ingestion of radioactive B12, sometimes even later. The time of peak excretion was fairly characteristic for the individual. Secondary peaks occasionally occurred, and only slight radioactivity usually remained after 24 hours. It is postulated that the delayed peak is related to the time it takes for B12 to be transported in the intestine to the point of absorption or to the duration of the intracellular metabolic processes of absorption. For most purposes the use of fractional urinary collections is not necessary.

scholarly journals Comparative studies on intrinsic factor and cobalophilin in different parts of the gastrointestinal tract of the pig

1978 ◽  
Vol 173 (3) ◽  
pp. 705-712 ◽  
Author(s):  
George Marcoullis ◽  
Hannele Merivuori ◽  
Ralph Gräsbeck
Keyword(s):  
Gastrointestinal Tract ◽  
Vitamin B12 ◽  
Gastric Juice ◽  
Neutral Type ◽  
Intrinsic Factor ◽  
Molecular Forms ◽  
Intrinsic Factors ◽  
Intestinal Juice ◽  
Pyloric Mucosa ◽  
Significant Difference

The vitamin B12 binders in the pig pyloric mucosa gastric and intestinal juice from the upper gastrointestinal tract were fractionated into only two molecular forms, classified as intrinsic factor and cobalophilin. The unsaturated vitamin B12-binding power due to cobalophilin was lower in the intestinal than in the gastric juice. Electrofocusing revealed that intrinsic factor and cobalophilin in the intestinal juice contained more of the ‘neutral’-type isoproteins, and the suggestion is made that this is due to enzyme activity. The gastric-juice intrinsic factor contained more acidic isoproteins, which supports the hypothesis that carbohydrate is added on to the polypeptide chain of this protein before it is secreted into gastric juice. The gastric- and intestinal-juice cobalophilins, studied also by electrofocusing, differed from that of pyloric mucosa and they appeared to be of salivary origin. With regard to molecular dimensions there was no significant difference between the intrinsic factors and cobalophilins from all sources studied. All cobalophilins had molecular weights by the formula of Svedberg of approx. 92500, Stokes radii of 4.62nm and sedimentation coefficients of 5.15S. The corresponding values for the intrinsic factors were 63600, 3.57nm and 4.38S. In addition, the intrinsic factors exhibited similar avidities for binding to the solubilized ileal intrinsic-factor receptor. Also the intrinsic factors and cobalophilins, irrespective of their source, bound to the analogous specific xenoantibodies with the same avidity. The present results demonstrate that intrinsic factor remains practically unaltered during its passage through the proximal intestine and render unlikely the speculations made about the presence of an endogenous binder for intrinsic factor as well as the existence of a ‘pancreatic intrinsic factor’. In addition, they are compatible with the theory that the interference by undegraded cobalophilin may be the reason for the abnormal vitamin B12 absorption observed in patients with pancreatic insufficiency.

scholarly journals Absorption of Cobalt60-Labeled Vitamin B12 After Subtotal Gastrectomy

Blood ◽  
1958 ◽  
Vol 13 (4) ◽  
pp. 339-347 ◽  
Author(s):  
FRITZ LOEWENSTEIN
Keyword(s):  
Urinary Excretion ◽  
Vitamin B12 ◽  
Proximal Gastrectomy ◽  
Intrinsic Factor ◽  
Subtotal Gastrectomy ◽  
Test Dose ◽  
Distal Portion ◽  
Normal Vitamin ◽  
Before And After ◽  
Vitamin B12 Absorption

Abstract Vitamin B12 absorption has been studied in patients with subtotal gastrectomy by means of the Co60 B12 urinary excretion test. Five patients tested before and after a conventional subtotal gastrectomy showed no significant change in absorption. Of 22 patients who were tested at various intervals after a conventional (distal) subtotal gastrectomy, 19 had normal vitiamin B12 absorption and three had low absorption that was corrected to normal by giving gastric juice with the test dose. Three patients who had had a proximal gastrectomy showed normal vitamin B12 absorption, indicating that intrinsic factor was being produced by the remaining distal portion of the stomach.

Treatment of pernicious anemia by oral administration of vitamin B12 and glandular mucoprotein recovered from gastric juice of humans

1952 ◽  
Vol 12 (1) ◽  
pp. 109 ◽  
Author(s):  
George B. Jerzy Glass ◽  
Linn J. Boyd ◽  
Michael A. Rubinstein ◽  
Chester S. Svigals
Keyword(s):  
Oral Administration ◽  
Vitamin B12 ◽  
Pernicious Anemia ◽  
Gastric Juice

scholarly journals Studies on Urinary Excretion of Vitamin B12Co60 in Pernicious Anemia for Determining Effective Dosage of Intrinsic Factor Concentrates

Blood ◽  
1956 ◽  
Vol 11 (4) ◽  
pp. 338-351 ◽  
Author(s):  
WILLIAM R. BEST ◽  
WILFRID F. WHITE ◽  
KENNETH C. ROBBINS ◽  
WENDELL A. LANDMANN ◽  
SANFORD L. STEELMAN
Keyword(s):  
Urinary Excretion ◽  
Vitamin B12 ◽  
Pernicious Anemia ◽  
Intrinsic Factor ◽  
Effective Dosage ◽  
Low Doses ◽  
Additional Increase ◽  
Linear Approach ◽  
Factor Concentrate ◽  
Made In

Abstract Studies were made in pernicious anemia patients on the urinary excretion of B12Co60 after a small oral dose followed by a large parenteral injection of nonradioactive vitamin B12. (1) Increasing doses of intrinsic factor concentrates give increasing excretions of radioactivity at low doses; little additional increase at moderate doses; and at times a subsequent diminution at excessive doses. Data on 34 tests of a particular intrinsic factor concentrate in 18 pernicious anemia patients tend to support an excretion proportional to the logarithm of intrinsic factor dosage at low to moderate levels, but do not exclude the possibility of a linear approach to a plateau. (2) Assay by hematologic response was compared with the urinary excretion tests in 13 pernicious anemia patients. This data shows a relation between the two tests though the correlation is far from complete. (3) Methods are outlined for testing all intrinsic factor preparations with the same amount of tracer vitamin B12 as will be incorporated commercially. More sensitive comparative tests of similar intrinsic factor preparations may be made using smaller amounts of B12Co60. (4) The literature is reviewed to determine which variations in technic might lead to the most reliable quantitation of intrinsic factor activity.

Sign in / Sign up

Export Citation Format

Share Document