1. The effects on the intrinsic tryptophan emission anisotropy of pepsin and pepsinogen solutions produced by (a) changes in temperature, (b) increases in viscosity with added glycerol at constant temperature and (c) decreases in lifetime through collisional quenching by potassium iodide were measured at several excitation wavelengths. The rotational-relaxation times calculated from results pro...

We describe the development of radioimmunoassays to measure both human pepsinogen A and pepsinogen C concentrations in serum. The antibodies were raised in goats by immunization with purified pepsinogen A or C. The affinity constants of the respective antibodies were 20.10(10) l/mol and 7.10(10) l/mol. Pepsinogens A and C were labeled with Na 125I by the chloramine T method. The binding between...

Serum pepsinogen activity was determined in the blood serum of 126 clinically healthy cows by the method of Paynter. After slaughter the cows studied were classified into three groups according to established macroscopic changes to the mucous membrane of the abomasum: a group without changes, a group with ulcers and a group with other changes. The prevalence of the appearance of abomasal ulcers...

Conventional in vitro studies of pepsinogen secretion have measured secretion into the bulk medium and have demonstrated the critical role of Ca2+ in the process. The present study was undertaken to obtain further details of the process of secretion and its relation to Ca2+changes over very short time periods. The relation between Ca2+ mobilization and exocytosis in an isolated individual pepti...

Rabbit antisera to pepsin and pepsinogen were characterized by several immunological criteria. Both antisera inhibited the rennet activity of pepsin. Antipepsinogen protected pepsin from alkaline denaturation. Using antipepsinogen, precipitin analysis at pH 5.5 indicated that the native enzyme resembles the precursor more closely than did the denatured enzyme. However, all three proteins have s...

Accurately identifying resistance to gastrointestinal nematode infections requires the ability to identify animals with low and high intensities of infection. The pathogenic effects of nematodes depend upon both the length and number of worms, neither of which can be measured in live animals. Indices that predict these quantities are urgently needed. Monthly fecal egg counts, bodyweights, IgA c...

1. Alkali (pH 7.6)-denatured pepsins from swine, cattle, and guinea pigs precipitate in swine pepsin antiserum. Similarly treated pepsins from the rabbit, chicken, and shark do not. 2. Pepsin antisera react with both pepsin and pepsinogen, but do not react with the serum proteins from the homologous species. 3. Pepsinogen antisera react with pepsinogen, but not with twice crystallized pepsin, n...

In a healthy population pepsinogen A and pepsinogen C increase with advancing age. As pepsinogen A and C are raised in chronic superficial gastritis which is caused by H pylori infection, we investigated whether H pylori is responsible for the age related increase of pepsinogen A and C. In H pylori positive blood transfusion donors serum pepsinogen A (mean (SD) 73 (35) micrograms/ml v 52 (19) m...