Trichinella pseudospiralis: X-ray analysis of the infected muscle cells and the muscle larva compartments after exponential growth of the larva in situ.

The distribution of nutrients such as Na, Cl, K, P, S, and Ca was investigated by energy-dispersive X-ray microanalysis (EDXA) on bulk-frozen mouse muscles infected with Trichinella pseudospiralis. In an attempt to gain information as to whether muscle larvae would modify the element status within muscles of their host. Significant increases in phosphorus concentrations within nurse cells and internal cells of the larva, e.g., the somatic muscle cells and the stichocytes, were shown. This could reflect changes in the energy metabolism and/or in the turnover of nucleic acids of the nurse cell. High phosphorus concentrations within the internal larva cells corresponded to high levels of expression of thymidylate synthase shown elsewhere in both T. pseudospiralis and T. spiralis muscle larvae, most likely reflecting more intensive DNA replication. Furthermore, the Na+-concentration gradient between the nurse cell and neighboring host muscle cells indicated the plasma membrane as a diffusion barrier for Na+. Moreover, the cuticle seemed to maintain the Cl--concentration gradient between the nurse cell and the internal cells of the larva. Nevertheless, the mechanisms involved in the transport of both ions, the collagen cuticle appeared, strong permeability that serves the transcuticular transport maintaining the Cl--concentration gradient.

Trichinella spiralis: X-ray analysis of the nurse cell-muscle larva complex after exponential growth of the larva.

The energy-dispersive X-ray analysis (EDXA) method was employed to determine how the exponential growth of the Trichinella spiralis larva affect the concentration of some metabolically active elements such as phosphorus, sulfur, sodium, chlorine, potassium, and calcium in host myocytes as well as inside the nurse cell-muscle larva complex. Two observations are noteworthy. First, the capsule of the complex reveals the highest Na+ and Cl-concentrations. We would suggest that these high Na+ and Cl-concentrations could be a part of the capsule-localized transport mechanisms covering the metabolic demands of the larva. Second, a substantial increase in the P concentration in the cells inside the complex, i.e., the nurse cell, somatic muscle of the larva, and larval stichosome was found. We postulate that energy metabolism in the nurse cell is entirely dependent on the metabolic requirements of the larva and that they remain together as one functional unit.