ARS | Publication request: MANGANESE DEPRIVATION IS NOT A PROPITIOUS STRESSOR OF BORON METABOLISM OR NUTRITION

Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: April 30, 1998
Publication Date: N/A

Technical Abstract: By using a nutritional stressor to enhance or change a response to a dietary lack of a trace element without a known biochemical function, insight about that function might be gained. Boron (B) apparently is of nutritional importance, but does not have a defined biochemical function. Because B alters nitrogen metabolism in plants by affecting the activation of manganese (Mn) enzymes, an experiment was performed to determine whether Mn deprivation would affect the response of rats to B deprivation. In a factorially arranged experiment, male Sprague-Dawley rats were assigned to groups of 10 and fed for 9 weeks a casein-ground corn-corn oil based diet containing per kg about 0.09 mg B and 0.10 mg Mn. The dietary variables were supplemental B at 0 and 3 mg/kg and Mn at 0 and 20 mg/kg. Rats fed the Mn deficient diet exhibited the usual signs of deficiency including decreased weight, hematocrit, hemoglobin, plasma amylase, plasma triglycerides, plasma cholesterol and tissue manganese concentrations, and increased blood urea nitrogen, plasma alkaline phosphatase and pancreatic amylase. Rats fed the B deficient diet exhibited increased hematocrit, hemoglobin, platelets and urea nitrogen in blood, and decreased tissue B concentrations. A significant interaction between Mn and B affected very few variables; of those, none were very remarkable. Manganese deficiency apparently prevented finding some signs of B deficiency including decreased plasma triglycerides and some tissue mineral composition changes. The findings indicate that Mn deficiency is not a nutritional stressor that will help gain insight into the biochemical function of B.