Effect of benzimidazoles on amino acid metabolism in Trichuris globulosa.
L-aspartic acid C14, L-alanine C14 and L-leucine C14 uptake by Trichuris globulosa was found to be a non-linear function of time and limiting substrate concentration. The uptake was rapid initially but achieved steady state possibly owing to the saturation of transport loci. Linear transformations of substrate saturation kinetics by Lineweaver-Burk plots of L-aspartic acid C14, L-alanine C14 and L-leucine C14 gave Kt values of 6.8 X 10(3) microM, 3.4 X 10(3) microM and 6.06 X 10(3) microM and Jmax of 0.769 mumoles/mg dry weight/min, 10 mumoles/mg dry weight/min and 0.285 mumoles/mg dry weight/min, respectively. The presence of benzimidazole drugs, thiabendazole and fenbendazole, markedly inhibited the uptake of amino acids at concentrations which did not affect the motility of the parasite. The amino acid transport was also found to be pH and temperature dependent. The uptaken amino acids were readily metabolized into different tissue fractions. Thiabendazole and fenbendazole significantly inhibited the incorporation of the three amino acids into the nematode's total protein fractions and trichloroacetic acid soluble fractions. These drugs also decreased the amount of radiocarbon of 14C-amino acids incorporated into CO2.
Jasra
N
N
Department of Zoology, Panjab University, Chandigarb, India.
Sanyal
S N
SN
Khera
S
S
D000042:Absorption / Q000187:drug effects; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology*; D014258:Trichuris / Q000187:drug effects* / Q000378:metabolism
D000596:Amino Acids; D001562:Benzimidazoles