The study of leucine and methionine transport in the gut of rats intoxicated with thiram.

Abstract

The effects of thiram on amino acids transport in rats jejunum were investigated. Using the gut everted sac method it was shown that 4 weeks intoxication with the pesticide (5% DL50 per os daily) caused time dependent inhibition in transport of C14-leucine and C14-methionine in the rat jejunum. In order to obtain further information, the influx of both amino acids into the jejunum slices was investigated in rats treated with thiram for 2 weeks. Over a range of amino acid concentrations (0-20 mM) the influx of these compounds was defined as the sum of a saturable term (active transport) and a linear term (passive transport). It was shown that thiram affected only the active transport of amino acids. The analysis of this transport for leucine using Lineweaver-Burk plots showed a decrease of the half-saturation constant (Kt), while the maximal value (Jm) remained unchanged. In the methionine transport study both kinetic constants were changed.