Selenium-mercury interaction during intestinal absorption of 75Se compounds in chicks

Area of Science:

• Environmental Toxicology
• Nutritional Biochemistry
• Trace Element Metabolism

Background:

• Mercury (Hg) and selenium (Se) are trace elements with known interactions.
• Understanding these interactions is crucial for assessing nutritional and toxicological impacts.

Purpose of the Study:

• To investigate the effects of inorganic and organic mercury on the intestinal absorption of different selenium compounds.
• To evaluate the nutritional significance of mercury-selenium interactions in the gut.

Main Methods:

• In vivo ligated duodenal loop procedure in White Leghorn cockerels.
• Administration of radiolabeled selenium (75Se) compounds with varying mercury concentrations.
• Analysis of selenium absorption and distribution in chicks fed diets supplemented with mercury and selenium.

Main Results:

• Inorganic mercury significantly inhibited the intestinal absorption of inorganic selenium compounds (selenite, selenate).
• Organic mercury (methylmercury) had minimal effect on selenium absorption.
• Dietary mercury reduced selenium transfer to the body by increasing intestinal accumulation, but did not affect methionine-Se absorption.
• Precipitation of selenite with inorganic mercury suggested direct luminal interaction.

Conclusions:

• Intestinal interaction between inorganic mercury and selenium occurs, particularly under high mercury-to-selenium ratios.
• These interactions are unlikely to be of major nutritional importance due to the specific conditions required.
• Organic mercury poses less of a risk regarding direct intestinal interaction with selenium absorption.