| Little is known about the dynamics of the uptake and utilization of acetate by Trichinella. Acetate is a precursor to acetyl-CoA, which is essential for many metabolic processes and may serve as a building block for essential macromolecules. Therefore the uptake of acetate by T. spiralis nurse cells (NCs) in the presence of acetic acid uniformly labeled with carbon-14 was studied in vitro. The kinetics of acetate transport were examined to determine whether the uptake of acetate was by diffusion or by a saturable process. The effects of glycine, proline and several Kreb's cycle intermediates, and ions, on the uptake of acetic acid were studied. The NCs were given acetate under starvation conditions to observe whether or not acetate was used to restore glycogen reserves. Finally, the C--14 labeled NCs were fractionated to trace the radio labeled carbon--14 from acetate.; The uptake of acetate increased significantly with time of incubation and short-term starvation. The uptake of acetate was a saturable process, indicating active acquisition of this compound by NCs. Acetate uptake under long-term starvation conditions was the exception. Starvation appears to either limit the use of acetate, or postpone rapid uptake of acetate. Physiological ranges in pH and temperature were the ranges at which acetate uptake was the highest. Acetate was incorporated into NC and larval macromolecules. All cellular components examined were found to contain label, with collagen and glycogen containing the majority of the label. Glycine and pyruvate lowered the uptake of acetate, while zinc and malate increased the uptake of acetate by NCs.; The uptake and incorporation of acetate by NCs provides evidence that they are metabolically active. Transport of acetate is via two energy dependent mechanisms, which have yet to be defined. |
