Subcellular in vivo 1H MR spectroscopy of Xenopus laevis oocytes.
In vivo magnetic resonance (MR) spectra are typically obtained from voxels whose spatial dimensions far exceed those of the cells they contain. This study was designed to evaluate the potential of localized MR spectroscopy to investigate subcellular phenomena. Using a high magnetic field and a home-built microscopy probe with large gradient field strengths, we achieved voxel sizes of (180 microm)3. In the large oocytes of the frog Xenopus laevis, this was small enough to allow the recording of the first compartment-selective in vivo MR spectra from the animal and vegetal cytoplasm as well as the nucleus. The two cytoplasmic regions differed in their lipid contents and NMR lineshape characteristics-differences that are not detectable with whole-cell NMR techniques. In the nucleus, the signal appeared to be dominated by water, whereas other contributions were negligible. We also used localized spectroscopy to monitor the uptake of diminazene acturate, an antitrypanosomal agent, into compartments of a single living oocyte. The resulting spectra from the nucleus and cytoplasm revealed different uptake kinetics for the two components of the drug and demonstrate that MR technology is on the verge of becoming a tool for cell biology.
Lee
Seung-Cheol
SC
Division of Proteome Research, Korea Basic Science Institute, Yusung-gu, Daejeon 305-333, Korea.
Cho
Jee-Hyun
JH
Mietchen
Daniel
D
Kim
Young-Sook
YS
Hong
Kwan Soo
KS
Lee
Chulhyun
C
Kang
Dongmin
D
Park
Ki Deok
KD
Choi
Byong-Seok
BS
Cheong
Chaejoon
C
D000818:Animals; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008055:Lipids / Q000032:analysis*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods*; D009865:Oocytes / Q000737:chemistry* / Q000648:ultrastructure*; D011522:Protons; D013347:Subcellular Fractions / Q000737:chemistry* / Q000648:ultrastructure*; D014982:Xenopus laevis
D008055:Lipids; D011522:Protons