| Project/Area Number |
63570186
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
寄生虫学(含医用動物学）
|
|---|
| Research Institution | 国立予防衛生研究所 |
|---|
Principal Investigator |
ENDO Takuro N. I. H., Department of Parasitology, Head of lst Division., 寄生虫部, 室長 (90072959)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KAWANAKA Masanori N. I. H., Department of Parasitology, Head of 3rd Division., 寄生虫部, 室長 (50109964)
|
|---|
| Project Period (FY) |
1988 – 1990
|
| Project Status |
Completed (Fiscal Year 1990)
|
| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1990: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1989: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1988: ¥1,000,000 (Direct Cost: ¥1,000,000)
|
|---|
| Keywords | Toxoplasma gondii / Tachyzoite / Methionine uptake / External ionic condition / Electrochemical H^+ gradient / Radiolabelling / トキソプラズマ原虫 / アミノ酸の取り込み / メチオニン / pH / アミノ酸吸収 / カリウムイオン / ナトリウムイオン / 細胞内pH / 塩素イオン / 硫酸塩 |
|---|
| Research Abstract |
The main reason for studying Toxoplasma is to learn more about its behavior in hopes of subsequently discovering a method for controlling or eradicating the disease it causes. Despite intensive study by experimental infection of various animals and tissue cultures, relatively little is known about this parasite's requirements for infection, survival and growth in a host cell. Nutritional studies of this parasite are complicate by its obligate parasitic nature. They are hidden from view of most of their life cycle. The extra-host cellular stage of the parasite, namely tachyzoite, which is easily obtainable in quantity seemed to be inactive or depressed, if any, in its metabolic activity. We examined influences of extracellular ions on several cellular events of this parasite including regulation of internal pH, motility and infectivity. We also studied possible occurrence of incorporation of ^<35>S-methionine by the tachyzoites in cell-free medium with varying external ionic conditions. In the present report, external ionic conditions, mainly K^+ and C1^-, are discussed in terms of electrochemical H^+ gradients across the parasite's membrane for cellular events of the tachyzoite in cell-free medium. A successful application of metabolic radiolabelling of toxoplasma proteins by ^<35>S-methionine let us possible tracer experiments of this parasitic protozoon. This method may also useful for screening anti-toxoplasma agints.
|
