QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Johnson, R. R. Articles by Sutton, T. S. Search for Related Content PubMed PubMed Citation Articles by Johnson, R. R. Articles by Sutton, T. S.

Divalent Minerals and Proteolytic Activity of Pancreas Tissue from Rats and Chicks Fed Manganese-Deficient Diets^{1, 2,}

Ohio Agricultural Experiment Station, Wooster

Incubation of chick and rat pancreatic homogenates in the presence of Ca⁺⁺ or Mn⁺⁺ ions prior to combination with the substrate increased the proteolytic activity of these homogenates. Similar incubation of purified chymotrypsin or trypsin provided a protection against autodigestion but did not increase the enzyme activity.

The ions Zn⁺⁺, Mg⁺⁺, Sr⁺⁺, and Co⁺⁺ exhibited some activation effect but were never as marked as Ca⁺⁺ or Mn⁺⁺. The pH for the maximum effect of Ca⁺⁺ was 5.9.

Pancreatic tissues from rats fed a manganese-deficient ration and chicks fed a practical corn soya ration without added manganese exhibited as much proteolytic activity as those of control animals. Homogenates prepared from pancreatic tissues from deficient animals had to be incubated longer with the divalent ions to obtain maximum proteolytic activity.

A dietary manganese deficiency in rats fed a purified type of diet did not lower the digestibility of the protein in the ration.

² A preliminary report of this work is published in Federation Proceedings, 10, 161, 1951 and in a Ph.D. Dissertation by Orville G. Bentley, University of Wisconsin, 1950.

³ Present address: Dean of Agriculture, South Dakota State College, Brookings.

Manuscript received 6 September 1958.