The effect of varying dietary zinc levels on the concentration and localization of zinc in rat bile-pancreatic fluid.

N. H. Reinstein, B. Lönnerdal, Carl L Keen, B. O. Schneeman, L. S. Hurley

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

To determine if zinc homeostasis occurs by zinc output from bile-pancreatic secretions, the bile-pancreatic duct and intestine of rats were surgically cannulated, and bile-pancreatic fluid was collected 2 h/d from the day of surgery to 8 d after surgery. The rats were fed diets containing 10, 100 or 1000 micrograms Zn/g diet before and after surgery. The effect of surgery itself was significant; food intake was initially lower than presurgery levels, but returned to presurgery levels by d 5. Protein and zinc concentrations, and carboxypeptidase A (CpA) and carboxypeptidase B (CpB) activities in bile-pancreatic fluid increased after surgery and leveled off at approximately d 6. Among the dietary zinc groups, the concentration of zinc in bile-pancreatic fluid varied significantly, whereas concentrations of calcium and copper did not. Zinc concentration in bile-pancreatic fluid for d 1-8 postsurgery averaged 1.8, 3.2 and 4.4 micrograms Zn/g, in the groups fed 10, 100 and 1000 micrograms Zn/g diet, respectively. Because the percent of zinc ingested that was secreted in bile-pancreatic fluid, estimated to be 57, 9.5 and 1.2% for the groups consuming the diets containing 10, 100 and 1000 micrograms Zn/g diet respectively, was not similar in the three groups, the quantity of zinc in bile-pancreatic fluid is not proportionally related to the amount of zinc ingested. Our results therefore suggest that zinc secretion in bile-pancreatic fluid does not play a major role in zinc homeostasis. Molecular localization of zinc in bile-pancreatic fluid and measurement of activity of CpA and CpB indicated that zinc in bile-pancreatic fluid is associated primarily with these digestive enzymes.

Original languageEnglish (US)
Pages (from-to)1060-1066
Number of pages7
JournalJournal of Nutrition
Volume117
Issue number6
StatePublished - Jun 1987
Externally publishedYes

ASJC Scopus subject areas

  • Food Science
  • Medicine (miscellaneous)

Fingerprint Dive into the research topics of 'The effect of varying dietary zinc levels on the concentration and localization of zinc in rat bile-pancreatic fluid.'. Together they form a unique fingerprint.

  • Cite this

    Reinstein, N. H., Lönnerdal, B., Keen, C. L., Schneeman, B. O., & Hurley, L. S. (1987). The effect of varying dietary zinc levels on the concentration and localization of zinc in rat bile-pancreatic fluid. Journal of Nutrition, 117(6), 1060-1066.