Studies on the free pool of amino acids of the cestodeHymenolepis diminuta

Abstract

Alteration of the free amino acid pool ofHymenolepis diminutawas observed following incubation of worms with a single exogenous amino acidin vitro, recovery from which depended upon the initial magnitude of alteration. The free amino acid pool of both rat small intestine andH. diminutawas rendered imbalanced after feeding a single dietary dose of proline. Recovery was more rapid in the host than in the parasite tissues. The quantitative dynamics of amino acid change with time were examined. The effects of amino acid variation upon the uptake and incorporation of lysine-C14into worm protein were examinedin vitro. Four amino acids altered lysine incorporation; aspartate stimulated incorporation while ornithine, arginine and histidine reduced variously the absolute amount of lysine uptake but produced relative stimulation of lysine incorporation. These data indicate that, in the system examined, short term variation of the free amino acid pool is unlikely to affect protein synthesis inH. diminuta. Data were obtained suggesting the possible occurrence of certain amino acid inter conversions inH. diminuta.